[FIR] Create special hidden override for Java signature clash due to rename

This fixes CharBuffer.get resolving to CharBuffer.charAt

#KT-61282 Fixed

compiler/testData/codegen/box/fullJdk/charBuffer.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_BACKEND_K2: JVM_IR
-//   Ignore reason: KT-61282
 // FULL_JDK
 
 import java.nio.CharBuffer

compiler/testData/codegen/box/specialBuiltins/charBuffer.kt

@@ -1,6 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_BACKEND_K2: JVM_IR
-//   Ignore reason: KT-61282
 // MODULE: lib
 // FILE: CharBuffer.java
 
@@ -34,6 +32,7 @@ public abstract class CharBuffer implements CharSequence {
 
 // MODULE: main(lib)
 // FILE: 1.kt
+abstract class KCB : CharBuffer()
 
 fun box(): String {
     val cb: CharBuffer = CharBuffer.impl()

compiler/testData/codegen/box/specialBuiltins/weirdCharBuffers.kt

@@ -0,0 +1,142 @@
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND_K1: ANY
+// ^KT-63431 CharBufferXAllInherited.create().get(0) is resolved incorrectly in K1
+
+// FILE: X.java
+public interface X {
+    char get(int index);
+}
+
+// FILE: CharBuffer.java
+public abstract class CharBuffer implements CharSequence {
+    public static CharBuffer create() {
+        return new CharBuffer() {
+            @Override public char charAt(int index) { return 'c'; }
+            @Override public char get(int index) { return 'g'; }
+            @Override public CharSequence subSequence(int start, int end) { return null; }
+            @Override public int length() { return 0; }
+        };
+    }
+    public abstract char charAt(int index);
+    public abstract char get(int index);
+}
+
+// FILE: CharBufferX.java
+public abstract class CharBufferX implements CharSequence, X {
+    public static CharBufferX create() {
+        return new CharBufferX() {
+            @Override public char charAt(int index) { return 'c'; }
+            @Override public char get(int index) { return 'g'; }
+            @Override public CharSequence subSequence(int start, int end) { return null; }
+            @Override public int length() { return 0; }
+        };
+    }
+    public abstract char charAt(int index);
+    public abstract char get(int index);
+}
+
+// FILE: NonCharSequenceBuffer.java
+public abstract class NonCharSequenceBuffer implements X {
+    public static NonCharSequenceBuffer create() {
+        return new NonCharSequenceBuffer() {
+            @Override public char charAt(int index) { return 'c'; }
+            @Override public char get(int index) { return 'g'; }
+        };
+    }
+    public abstract char charAt(int index);
+    public abstract char get(int index);
+}
+
+// FILE: CharBufferCharAtInherited.java
+public abstract class CharBufferCharAtInherited implements CharSequence {
+    public static CharBufferCharAtInherited create() {
+        return new CharBufferCharAtInherited() {
+            @Override public char charAt(int index) { return 'c'; }
+            @Override public char get(int index) { return 'g'; }
+            @Override public CharSequence subSequence(int start, int end) { return null; }
+            @Override public int length() { return 0; }
+        };
+    }
+    public abstract char get(int index);
+}
+
+// FILE: CharBufferXAllInherited.java
+public abstract class CharBufferXAllInherited implements CharSequence, X {
+    public static CharBufferXAllInherited create() {
+        return new CharBufferXAllInherited() {
+            @Override public char charAt(int index) { return 'c'; }
+            @Override public char get(int index) { return 'g'; }
+            @Override public CharSequence subSequence(int start, int end) { return null; }
+            @Override public int length() { return 0; }
+        };
+    }
+}
+
+// FILE: Y.java
+public abstract class Y {
+    protected abstract char get(int index);
+}
+
+// FILE: CharBufferXYAllInherited.java
+public abstract class CharBufferXYAllInherited extends Y implements CharSequence, X {
+    public static CharBufferXYAllInherited create() {
+        return new CharBufferXYAllInherited() {
+            @Override public char charAt(int index) { return 'c'; }
+            @Override public char get(int index) { return 'g'; }
+            @Override public CharSequence subSequence(int start, int end) { return null; }
+            @Override public int length() { return 0; }
+        };
+    }
+}
+
+// FILE: CharAt.java
+public interface CharAt {
+    char charAt(int index);
+}
+
+// FILE: CharBufferXYCharAt.java
+public abstract class CharBufferXYCharAt extends Y implements CharSequence, X, CharAt {
+    public static CharBufferXYCharAt create() {
+        return new CharBufferXYCharAt() {
+            @Override public char charAt(int index) { return 'c'; }
+            @Override public char get(int index) { return 'g'; }
+            @Override public CharSequence subSequence(int start, int end) { return null; }
+            @Override public int length() { return 0; }
+        };
+    }
+}
+
+// FILE: box.kt
+
+fun box(): String {
+    if (CharBuffer.create().get(0) != 'g') return "FAIL 1"
+    if ((CharBuffer.create() as CharSequence).get(0) != 'c') return "FAIL 2"
+
+    if (CharBufferX.create().get(0) != 'g') return "FAIL 3"
+    if ((CharBufferX.create() as CharSequence).get(0) != 'c') return "FAIL 4"
+    if ((CharBufferX.create() as X).get(0) != 'g') return "FAIL 5"
+
+    if (NonCharSequenceBuffer.create().charAt(0) != 'c') return "FAIL 6"
+    if (NonCharSequenceBuffer.create().get(0) != 'g') return "FAIL 7"
+    if ((NonCharSequenceBuffer.create() as X).get(0) != 'g') return "FAIL 8"
+
+    if (CharBufferCharAtInherited.create().get(0) != 'g') return "FAIL 9"
+    if ((CharBufferCharAtInherited.create() as CharSequence).get(0) != 'c') return "FAIL 10"
+
+    if (CharBufferXAllInherited.create().get(0) != 'g') return "FAIL 11"
+    if ((CharBufferXAllInherited.create() as CharSequence).get(0) != 'c') return "FAIL 12"
+    if ((CharBufferXAllInherited.create() as X).get(0) != 'g') return "FAIL 13"
+
+    if (CharBufferXYAllInherited.create().get(0) != 'g') return "FAIL 14"
+    if ((CharBufferXYAllInherited.create() as CharSequence).get(0) != 'c') return "FAIL 15"
+    if ((CharBufferXYAllInherited.create() as X).get(0) != 'g') return "FAIL 16"
+    if ((CharBufferXYAllInherited.create() as Y).get(0) != 'g') return "FAIL 17"
+
+    if (CharBufferXYCharAt.create().get(0) != 'g') return "FAIL 18"
+    if ((CharBufferXYCharAt.create() as CharSequence).get(0) != 'c') return "FAIL 19"
+    if ((CharBufferXYCharAt.create() as X).get(0) != 'g') return "FAIL 20"
+    if ((CharBufferXYCharAt.create() as Y).get(0) != 'g') return "FAIL 21"
+    if ((CharBufferXYCharAt.create() as CharAt).charAt(0) != 'c') return "FAIL 22"
+
+    return "OK"
+}

compiler/testData/diagnostics/tests/j+k/collectionOverrides/weirdCharBuffers.kt

@@ -0,0 +1,105 @@
+// FIR_IDENTICAL
+// SCOPE_DUMP: CharBuffer:get;charAt, CharBufferX:get;charAt, NonCharSequenceBuffer:get;charAt, NonCharBuffer:get;charAt, CharBufferXAllInherited:get;charAt, CharBufferXYAllInherited:get;charAt, CharBufferXYCharAt:get;charAt
+
+// FILE: X.java
+public interface X {
+    char get(int index);
+}
+
+// FILE: CharBuffer.java
+public abstract class CharBuffer implements CharSequence {
+    // Should override 'kotlin.CharSequence.get'
+    public final char charAt(int index) {
+        return get(position() + checkIndex(index, 1));
+    }
+
+    // The key problem here is that `get` has the same signature as kotlin.CharSequence.get but completely different semantics
+    // Should override nothing
+    public abstract char get(int index);
+}
+
+// FILE: CharBufferX.java
+public abstract class CharBufferX implements CharSequence, X {
+    // Should override 'kotlin.CharSequence.get'
+    public final char charAt(int index) {
+        return get(position() + checkIndex(index, 1));
+    }
+
+    // Should override X.get
+    public abstract char get(int index);
+}
+
+// FILE: NonCharSequenceBuffer.java
+public abstract class NonCharSequenceBuffer implements X {
+    // Should override nothing and be available as 'charAt', not as 'get'
+    public final char charAt(int index) {
+        return get(position() + checkIndex(index, 1));
+    }
+
+    // Should override 'X.get'
+    public abstract char get(int index);
+}
+
+// FILE: NonCharBuffer.java
+public abstract class NonCharBuffer implements CharSequence {
+    // Not overriding charAt explicitly but inherited through kotlin.CharSequence.get
+
+    // Should override nothing
+    public abstract char get(int index);
+}
+
+// FILE: CharBufferXAllInherited.java
+public abstract class CharBufferXAllInherited implements CharSequence, X {
+}
+
+// FILE: Y.java
+public class Y {
+    protected abstract char get(int index);
+}
+
+// FILE: CharBufferXYAllInherited.java
+public abstract class CharBufferXYAllInherited extends Y implements CharSequence, X {
+}
+
+// FILE: CharAt.java
+public interface CharAt {
+    char charAt(int index);
+}
+
+// FILE: CharBufferXYCharAt.java
+public class CharBufferXYCharAt extends Y implements CharSequence, X, CharAt {
+}
+
+// FILE: main.kt
+
+fun test(
+    charBuffer: CharBuffer,
+    charBufferX: CharBufferX,
+    nonCharSequenceBuffer: NonCharSequenceBuffer,
+    nonCharBuffer: NonCharBuffer,
+    charBufferXAllInherited: CharBufferXAllInherited,
+    charBufferXYAllInherited: CharBufferXYAllInherited,
+    charBufferXYCharAt: CharBufferXYCharAt,
+) {
+    charBuffer.get(0)
+    (charBuffer as CharSequence).get(0)
+
+    charBufferX.get(0)
+    (charBufferX as CharSequence).get(0)
+
+    nonCharSequenceBuffer.get(0)
+    nonCharSequenceBuffer.charAt(0)
+
+    nonCharBuffer.get(0)
+    (nonCharBuffer as CharSequence).get(0)
+
+    charBufferXAllInherited.get(0)
+    (charBufferXAllInherited as CharSequence).get(0)
+
+    charBufferXYAllInherited.get(0)
+    (charBufferXYAllInherited as CharSequence).get(0)
+
+    charBufferXYCharAt.get(0)
+    (charBufferXYCharAt as CharSequence).get(0)
+    (charBufferXYCharAt as CharAt).charAt(0)
+}

compiler/testData/diagnostics/tests/j+k/collectionOverrides/weirdCharBuffers.overrides.txt

@@ -0,0 +1,40 @@
+CharBuffer:
+  [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBuffer [id: 0]
+  [Enhancement]: public final operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBuffer [id: 0]
+    [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Use site scope of kotlin/CharSequence [id: 1]
+
+CharBufferX:
+  [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBufferX [id: 0]
+    [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /X [id: 1]
+  [Enhancement]: public final operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBufferX [id: 0]
+    [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Use site scope of kotlin/CharSequence [id: 1]
+
+NonCharSequenceBuffer:
+  [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /NonCharSequenceBuffer [id: 0]
+    [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /X [id: 1]
+  [Enhancement]: public final fun charAt(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /NonCharSequenceBuffer [id: 0]
+
+NonCharBuffer:
+  [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /NonCharBuffer [id: 0]
+  [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /NonCharBuffer [id: 0]
+    [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Use site scope of kotlin/CharSequence [id: 1]
+
+CharBufferXAllInherited:
+  [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBufferXAllInherited [id: 0]
+    [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Use site scope of kotlin/CharSequence [id: 1]
+  [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBufferXAllInherited [id: 0]
+
+CharBufferXYAllInherited:
+  [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBufferXYAllInherited [id: 0]
+    [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Use site scope of kotlin/CharSequence [id: 1]
+  [IntersectionOverride]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBufferXYAllInherited [id: 0]
+    [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /X [id: 1]
+    [Enhancement]: protected/*protected and package*/ abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /Y [id: 2]
+
+CharBufferXYCharAt:
+  [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBufferXYCharAt [id: 0]
+    [Library]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Use site scope of kotlin/CharSequence [id: 1]
+    [RenamedForOverride]: public abstract fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharAt [id: 2]
+  [IntersectionOverride]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /CharBufferXYCharAt [id: 0]
+    [Enhancement]: public abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /X [id: 1]
+    [Enhancement]: protected/*protected and package*/ abstract operator fun get(index: R|kotlin/Int|): R|kotlin/Char| from Java enhancement scope for /Y [id: 2]