Introduce Variable: Do not replace assignment left-hand sides

#KT-14240 Fixed

idea/testData/refactoring/introduceVariable/arrayAssignment.kt

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+class Foo(var bar: IntArray)
+
+fun test() {
+    val foo = Foo(IntArray(1) { 1 })
+    println(<selection>foo.bar</selection>)
+    foo.bar[0] = foo.bar[0] + 1
+}

idea/testData/refactoring/introduceVariable/arrayAssignment.kt.after

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+class Foo(var bar: IntArray)
+
+fun test() {
+    val foo = Foo(IntArray(1) { 1 })
+    val message = foo.bar
+    println(message)
+    message[0] = message[0] + 1
+}

idea/testData/refactoring/introduceVariable/onAssignmentLHS.kt

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+class Foo(var bar: Int)
+
+fun test() {
+    val foo = Foo(1)
+    println(foo.bar)
+    <selection>foo.bar</selection> = foo.bar + 1
+}

idea/testData/refactoring/introduceVariable/onAssignmentLHS.kt.conflicts

@@ -0,0 +1 @@
+Cannot perform refactoring without an expression

idea/testData/refactoring/introduceVariable/selectorAssignment.kt

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+class Foo(var bar: Bar)
+class Bar(var baz: Int)
+
+fun test() {
+    val foo = Foo(Bar(1))
+    println(<selection>foo.bar</selection>)
+    foo.bar.baz = foo.bar.baz + 1
+}

idea/testData/refactoring/introduceVariable/selectorAssignment.kt.after

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+class Foo(var bar: Bar)
+class Bar(var baz: Int)
+
+fun test() {
+    val foo = Foo(Bar(1))
+    val message = foo.bar
+    println(message)
+    message.baz = message.baz + 1
+}

idea/testData/refactoring/introduceVariable/skipUsageInAssignmentLHS.kt

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+class Foo(var bar: Int)
+
+fun test() {
+    val foo = Foo(1)
+    println(<selection>foo.bar</selection>)
+    foo.bar = foo.bar + 1
+}

idea/testData/refactoring/introduceVariable/skipUsageInAssignmentLHS.kt.after

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+class Foo(var bar: Int)
+
+fun test() {
+    val foo = Foo(1)
+    val message = foo.bar
+    println(message)
+    foo.bar = message + 1
+}