[FIR] Handle varargs in overloaded indexed access operator.

compiler/testData/codegen/box/increment/classVarargGetSet.kt

@@ -0,0 +1,29 @@
+object A {
+    var x = 0
+    var gets = 0
+    var sets = 0
+
+    operator fun get(vararg va: Int): Int {
+        for (i in va) {
+            gets += i
+        }
+        return x
+    }
+
+    operator fun set(vararg va: Int, value: Int) {
+        for (i in va) {
+            sets += i
+        }
+        x = value
+    }
+}
+
+fun box(): String {
+    A.x = 0
+    val xx = A[1, 2, 3]++
+    if (xx != 0) return "Failed xx: $xx"
+    if (A.x != 1) return "Failed A.x: ${A.x}"
+    if (A.gets != 6) return "Failed A.gets: ${A.gets}"
+    if (A.sets != 6) return "Failed A.sets: ${A.sets}"
+    return "OK"
+}

compiler/testData/diagnostics/tests/checkArguments/arrayAccessSet.fir.kt

@@ -28,8 +28,8 @@ fun test() {
     B[0] = 2.72
     B[0] = true
 
-    <!INAPPLICABLE_CANDIDATE!>D[0] = ""<!>
-    <!INAPPLICABLE_CANDIDATE!>D[0] = 2.72<!>
+    D[0] = ""
+    D[0] = 2.72
 
     <!INAPPLICABLE_CANDIDATE!>Z[0] = ""<!>
 }

compiler/testData/ir/irText/expressions/kt28456a.fir.txt

@@ -26,8 +26,13 @@ FILE fqName:<root> fileName:/kt28456a.kt
   FUN name:testSimpleAssignment visibility:public modality:FINAL <> (a:<root>.A) returnType:kotlin.Unit
     VALUE_PARAMETER name:a index:0 type:<root>.A
     BLOCK_BODY
-      ERROR_CALL 'Unresolved reference: <Inapplicable(INAPPLICABLE_ARGUMENTS_MAPPING_ERROR): /set>#' type=kotlin.Unit
-        CONST Int type=kotlin.Int value=1
-        CONST Int type=kotlin.Int value=2
-        CONST Int type=kotlin.Int value=3
-        CONST Int type=kotlin.Int value=0
+      BLOCK type=kotlin.Unit origin=ARGUMENTS_REORDERING_FOR_CALL
+        VAR IR_TEMPORARY_VARIABLE name:tmp_0 type:kotlin.IntArray [val]
+          VARARG type=kotlin.IntArray varargElementType=kotlin.Int
+            CONST Int type=kotlin.Int value=1
+            CONST Int type=kotlin.Int value=2
+            CONST Int type=kotlin.Int value=3
+        CALL 'public final fun set (vararg i: kotlin.Int, v: kotlin.Int): kotlin.Unit [operator] declared in <root>' type=kotlin.Unit origin=null
+          $receiver: GET_VAR 'a: <root>.A declared in <root>.testSimpleAssignment' type=<root>.A origin=null
+          i: GET_VAR 'val tmp_0: kotlin.IntArray [val] declared in <root>.testSimpleAssignment' type=kotlin.IntArray origin=null
+          v: CONST Int type=kotlin.Int value=0