JS: improve name clash checker to handle complicated cases

See KT-18010

compiler/testData/diagnostics/testsWithJsStdLib/name/bridgeClash.kt

@@ -0,0 +1,18 @@
+interface I {
+    fun foo()
+}
+
+interface J {
+    @JsName("bar")
+    fun foo()
+}
+
+interface K : I, J {
+    override fun foo()
+}
+
+interface L : K {
+    <!JS_NAME_CLASH!>override fun foo()<!>
+
+    <!JS_NAME_CLASH!>fun bar()<!>
+}

compiler/testData/diagnostics/testsWithJsStdLib/name/bridgeClash.txt

@@ -0,0 +1,30 @@
+package
+
+public interface I {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface J {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @kotlin.js.JsName(name = "bar") public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface K : I, J {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*2*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface L : K {
+    public abstract fun bar(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithJsStdLib/name/nameSwapInOverride.kt

@@ -0,0 +1,21 @@
+interface I {
+    @JsName("bar")
+    fun foo()
+
+    @JsName("foo")
+    fun bar()
+}
+
+interface J {
+    fun foo()
+
+    fun bar()
+}
+
+class A : I, J {
+    // Duplicate diagnostics are expected here, since `bar()` function gets both `foo` and `bar` names and clashes with both
+    // names of `foo()` function.
+    <!JS_NAME_CLASH, JS_NAME_CLASH!>override fun bar()<!> {}
+
+    <!JS_NAME_CLASH, JS_NAME_CLASH!>override fun foo()<!> {}
+}

compiler/testData/diagnostics/testsWithJsStdLib/name/nameSwapInOverride.txt

@@ -0,0 +1,26 @@
+package
+
+public final class A : I, J {
+    public constructor A()
+    public open override /*2*/ fun bar(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface I {
+    @kotlin.js.JsName(name = "foo") public abstract fun bar(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @kotlin.js.JsName(name = "bar") public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface J {
+    public abstract fun bar(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}