Don't report the same diagnsotics several times

compiler/testData/diagnostics/tests/inference/builderInference/constraints/violating.kt

@@ -8,26 +8,26 @@ interface A {
 @ExperimentalStdlibApi
 fun main() {
     buildList {
-        add(<!CONSTANT_EXPECTED_TYPE_MISMATCH, CONSTANT_EXPECTED_TYPE_MISMATCH!>3<!>)
+        add(<!CONSTANT_EXPECTED_TYPE_MISMATCH!>3<!>)
         object : A {
             override fun foo(): MutableList<String> = this@buildList
         }
     }
     buildList {
-        add(<!CONSTANT_EXPECTED_TYPE_MISMATCH, CONSTANT_EXPECTED_TYPE_MISMATCH!>3<!>)
+        add(<!CONSTANT_EXPECTED_TYPE_MISMATCH!>3<!>)
         val x: String = get(0)
     }
     buildList {
-        add(<!TYPE_MISMATCH, TYPE_MISMATCH!>"3"<!>)
+        add(<!TYPE_MISMATCH!>"3"<!>)
         val x: MutableList<Int> = this@buildList
     }
     buildList {
         val y: CharSequence = ""
-        add(<!TYPE_MISMATCH, TYPE_MISMATCH, TYPE_MISMATCH!>y<!>)
+        add(<!TYPE_MISMATCH, TYPE_MISMATCH!>y<!>)
         val x: MutableList<String> = this@buildList
     }
     buildList {
-        add(<!TYPE_MISMATCH, TYPE_MISMATCH!>""<!>)
+        add(<!TYPE_MISMATCH!>""<!>)
         val x: StringBuilder = get(0)
     }
 }