Multi-declarations supported in all flavours of for loops

(KT-2635 Support iteration with multiple range variable in JVM back-end)
 #KT-2635 Fixed

compiler/testData/codegen/multiDecl/forRange/explicitRangeToWithDot/int/MultiDeclForComponentExtensions.kt

@@ -0,0 +1,15 @@
+fun Int.component1() = this + 1
+fun Int.component2() = this + 2
+
+fun doTest(): String {
+    var s = ""
+    for ((a, b) in 0.rangeTo(2)) {
+      s += "$a:$b;"
+    }
+    return s
+}
+
+fun box(): String {
+  val s = doTest()
+  return if (s == "1:2;2:3;3:4;") "OK" else "fail: $s"
+}

compiler/testData/codegen/multiDecl/forRange/explicitRangeToWithDot/int/MultiDeclForComponentExtensionsValCaptured.kt

@@ -0,0 +1,15 @@
+fun Int.component1() = this + 1
+fun Int.component2() = this + 2
+
+fun doTest(): String {
+    var s = ""
+    for ((a, b) in 0.rangeTo(2)) {
+      s += {"$a:$b;"}()
+    }
+    return s
+}
+
+fun box(): String {
+  val s = doTest()
+  return if (s == "1:2;2:3;3:4;") "OK" else "fail: $s"
+}

compiler/testData/codegen/multiDecl/forRange/explicitRangeToWithDot/int/MultiDeclForComponentMemberExtensions.kt

@@ -0,0 +1,17 @@
+class M {
+  fun Int.component1() = this + 1
+  fun Int.component2() = this + 2
+
+  fun doTest(): String {
+      var s = ""
+      for ((a, b) in 0.rangeTo(2)) {
+        s += "$a:$b;"
+      }
+      return s
+  }
+}
+
+fun box(): String {
+  val s = M().doTest()
+  return if (s == "1:2;2:3;3:4;") "OK" else "fail: $s"
+}

compiler/testData/codegen/multiDecl/forRange/explicitRangeToWithDot/int/MultiDeclForComponentMemberExtensionsInExtensionFunction.kt

@@ -0,0 +1,17 @@
+class M {
+  fun Int.component1() = this + 1
+  fun Int.component2() = this + 2
+}
+
+fun M.doTest(): String {
+    var s = ""
+    for ((a, b) in 0.rangeTo(2)) {
+      s += "$a:$b;"
+    }
+    return s
+}
+
+fun box(): String {
+  val s = M().doTest()
+  return if (s == "1:2;2:3;3:4;") "OK" else "fail: $s"
+}