Elvis DFA: now only left part is taken into account #KT-9100 Fixed

I had to fix a few incorrect tests using something like x!! in Elvis right part, and also one bug in our code

compiler/testData/diagnostics/tests/smartCasts/elvisExclExcl.kt

@@ -0,0 +1,9 @@
+// Based on KT-9100
+fun test(x: Any?, y: Any?): Any {
+    val z = x ?: y!!
+    y<!UNSAFE_CALL!>.<!>hashCode()
+    // !! / ?. is necessary here, because y!! above may not be executed
+    y?.hashCode()
+    y!!.hashCode()
+    return z
+}

compiler/testData/diagnostics/tests/smartCasts/elvisExclExcl.txt

@@ -0,0 +1,3 @@
+package
+
+public fun test(/*0*/ x: kotlin.Any?, /*1*/ y: kotlin.Any?): kotlin.Any

compiler/testData/diagnostics/tests/smartCasts/elvisExclExclMerge.kt

@@ -0,0 +1,6 @@
+fun test(x: Any?): Any {
+    val z = x ?: x!!
+    // x is not null in both branches
+    <!DEBUG_INFO_SMARTCAST!>x<!>.hashCode()
+    return z
+}

compiler/testData/diagnostics/tests/smartCasts/elvisExclExclMerge.txt

@@ -0,0 +1,3 @@
+package
+
+public fun test(/*0*/ x: kotlin.Any?): kotlin.Any

compiler/testData/diagnostics/tests/smartCasts/elvisExclExclPlatform.kt

@@ -0,0 +1,27 @@
+// FILE: p/My.java
+
+package p;
+
+import org.jetbrains.annotations.*;
+
+class My {
+    @Nullable static String create() {
+        return "";
+    }
+}
+
+// FILE: test.kt
+
+package p
+
+fun bar(x: String) = x
+
+fun test(x: String?): Any {
+    val y = My.create()
+    val z = x ?: y!!
+    bar(<!TYPE_MISMATCH!>y<!>)
+    // !! / ?. is necessary here, because y!! above may not be executed
+    y?.hashCode()
+    y!!.hashCode()
+    return z
+}

compiler/testData/diagnostics/tests/smartCasts/elvisExclExclPlatform.txt

@@ -0,0 +1,16 @@
+package
+
+package p {
+    public fun bar(/*0*/ x: kotlin.String): kotlin.String
+    public fun test(/*0*/ x: kotlin.String?): kotlin.Any
+
+    public/*package*/ open class My {
+        public/*package*/ constructor My()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        // Static members
+        org.jetbrains.annotations.Nullable() public/*package*/ open fun create(): kotlin.String?
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/loops/assignElvisIfBreakInsideWhileTrue.kt

@@ -3,8 +3,8 @@ public fun foo(x: String?, y: String?): Int {
         val z = x ?: if (y == null) break else <!DEBUG_INFO_SMARTCAST!>y<!>
         // z is not null in both branches
         z.length()
-        // y is not null in both branches
-        <!DEBUG_INFO_SMARTCAST!>y<!>.length()
+        // y is nullable if x != null
+        y<!UNSAFE_CALL!>.<!>length()
     }
     // y is null because of the break
     return y<!UNSAFE_CALL!>.<!>length()

compiler/testData/diagnostics/tests/smartCasts/loops/elvisIfBreakInsideWhileTrue.kt

@@ -1,8 +1,8 @@
 public fun foo(x: String?, y: String?): Int {
     while (true) {
         x ?: if (y == null) break
-        // y is not null in both branches
-        <!DEBUG_INFO_SMARTCAST!>y<!>.length()
+        // y is nullable if x != null
+        y<!UNSAFE_CALL!>.<!>length()
     }
     // y is null because of the break
     return y<!UNSAFE_CALL!>.<!>length()

compiler/testData/diagnostics/tests/smartCasts/loops/elvisLeftBreakInsideWhileTrue.kt

@@ -1,8 +1,8 @@
 public fun foo(x: String?, y: String?): Int {
     while (true) {
         (if (x != null) break else y) ?: y!!
-        // x is not null in both branches
-        <!DEBUG_INFO_SMARTCAST!>y<!>.length()
+        // y is not null in both branches but it's hard to determine
+        y<!UNSAFE_CALL!>.<!>length()
     }
     // y can be null because of the break
     return y<!UNSAFE_CALL!>.<!>length()