KT-1273 Unused assignment - should highlight assignment instead of expression

#KT-1273 Fixed

idea/testData/checker/IncDec.kt

@@ -12,7 +12,7 @@ fun testIncDec() {
   x = <warning>x++</warning>
   x = <warning>x--</warning>
   x = ++x
-  x = <warning>--x</warning>
+  <warning>x =</warning> --x
 }
 
 class WrongIncDec() {
@@ -42,5 +42,5 @@ fun testUnitIncDec() {
   x = <warning>x<error>++</error></warning>
   x = <warning>x<error>--</error></warning>
   x = <error>++</error>x
-  x = <warning><error>--</error>x</warning>
+  <warning>x =</warning> <error>--</error>x
 }

idea/testData/checker/Unused.kt

@@ -9,7 +9,7 @@ fun test(<warning textAttributesKey="NOT_USED_ELEMENT_ATTRIBUTES">unusedParam</w
 
   val <warning textAttributesKey="NOT_USED_ELEMENT_ATTRIBUTES">unusedVar</warning> = ":(" // UNUSED_VARIABLE
   var <warning textAttributesKey="NOT_USED_ELEMENT_ATTRIBUTES">neverAccessed</warning>: Int // ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE
-  neverAccessed = <warning>2</warning>
+  <warning>neverAccessed =</warning> 2
 
   var redundantInitializer = <warning textAttributesKey="NOT_USED_ELEMENT_ATTRIBUTES">1</warning> // VARIABLE_WITH_REDUNDANT_INITIALIZER
   redundantInitializer = 2

idea/testData/checker/infos/SmartCasts.kt

@@ -165,7 +165,7 @@ fun declarations(a: Any?) {
 fun vars(a: Any?) {
     var <warning>b</warning>: Int = 0
     if (a is Int) {
-        b = <warning><info descr="Smart cast to kotlin.Int">a</info></warning>
+        <warning>b =</warning> <info descr="Smart cast to kotlin.Int">a</info>
     }
 }
 fun returnFunctionLiteralBlock(<info>a</info>: Any?): Function0<Int> {

idea/testData/checker/regression/AssignmentsUnderOperators.kt

@@ -2,5 +2,5 @@ fun test() {
   var a : Any? = null
   if (a is Any) else a = null;
   while (a is Any) a = null
-  while (true) a = <warning>null</warning>
+  while (true) <warning>a =</warning> null
 }