KT-2643 Support multi-declarations in Data-Flow analysis

#KT-2643 fixed

compiler/testData/diagnostics/tests/declarationChecks/ComponentFunctionReturnTypeMismatch.kt

@@ -3,6 +3,6 @@ class A {
     fun component2() : Int = 2
 }
 
-fun a(<!UNUSED_PARAMETER!>aa<!> : A) {
-    val (a: String, b1: String) = <!COMPONENT_FUNCTION_RETURN_TYPE_MISMATCH, COMPONENT_FUNCTION_RETURN_TYPE_MISMATCH!>aa<!>
+fun a(aa : A) {
+    val (<!UNUSED_VARIABLE!>a<!>: String, <!UNUSED_VARIABLE!>b1<!>: String) = <!COMPONENT_FUNCTION_RETURN_TYPE_MISMATCH, COMPONENT_FUNCTION_RETURN_TYPE_MISMATCH!>aa<!>
 }

compiler/testData/diagnostics/tests/declarationChecks/DataFlowInfoInMultiDecl.kt

@@ -5,10 +5,10 @@ class A {
 
 fun a(aa : A?, b : Any) {
     if (aa != null) {
-        val (a1, b1) = aa;
+        val (<!UNUSED_VARIABLE!>a1<!>, <!UNUSED_VARIABLE!>b1<!>) = aa;
     }
 
     if (b is A) {
-        val (a1, b1) = b;
+        val (<!UNUSED_VARIABLE!>a1<!>, <!UNUSED_VARIABLE!>b1<!>) = b;
     }
-}
+}

compiler/testData/diagnostics/tests/declarationChecks/MultiDeclarationErrors.kt

@@ -9,7 +9,7 @@ class MyClass2 {}
 <!CONFLICTING_OVERLOADS!>fun MyClass2.component1()<!> = 1.2
 <!CONFLICTING_OVERLOADS!>fun MyClass2.component1()<!> = 1.3
 
-fun test(<!UNUSED_PARAMETER!>mc1<!>: MyClass, <!UNUSED_PARAMETER!>mc2<!>: MyClass2) {
+fun test(mc1: MyClass, mc2: MyClass2) {
     val (a, b) = <!COMPONENT_FUNCTION_MISSING, COMPONENT_FUNCTION_MISSING!>mc1<!>
     val (c) = <!COMPONENT_FUNCTION_AMBIGUITY!>mc2<!>
 

compiler/testData/diagnostics/tests/declarationChecks/RedeclarationsInMultiDecl.kt

@@ -4,11 +4,11 @@ class A {
 }
 
 fun a() {
-    val (<!REDECLARATION!>a<!>, <!REDECLARATION!>a<!>) = A()
-    val (x, <!REDECLARATION!>y<!>) = A();
+    val (<!REDECLARATION, UNUSED_VARIABLE!>a<!>, <!REDECLARATION, UNUSED_VARIABLE!>a<!>) = A()
+    val (<!UNUSED_VARIABLE!>x<!>, <!REDECLARATION, UNUSED_VARIABLE!>y<!>) = A();
     val <!REDECLARATION!>b<!> = 1
     use(b)
-    val (<!REDECLARATION!>b<!>, <!REDECLARATION!>y<!>) = A();
+    val (<!REDECLARATION, UNUSED_VARIABLE!>b<!>, <!REDECLARATION, UNUSED_VARIABLE!>y<!>) = A();
 }
 
 

compiler/testData/diagnostics/tests/declarationChecks/kt2631_MultipleDeclaration.kt

@@ -10,7 +10,7 @@ class MyClass2 {}
 
 fun MyClass2.component1() = 1.2
 
-fun test(<!UNUSED_PARAMETER!>mc1<!>: MyClass, <!UNUSED_PARAMETER!>mc2<!>: MyClass2) {
+fun test(mc1: MyClass, mc2: MyClass2) {
     val (a, b) = mc1
     a : Int
     b : String

compiler/testData/diagnostics/tests/declarationChecks/kt2643MultiDeclInControlFlow.kt

@@ -0,0 +1,27 @@
+//KT-2643 Support multi-declarations in Data-Flow analysis
+package n
+
+class C {
+    fun component1() = 1
+    fun component2() = 2
+}
+
+fun test1(c: C) {
+    val (<!UNUSED_VARIABLE!>a<!>, <!UNUSED_VARIABLE!>b<!>) = c
+}
+
+fun test2(c: C) {
+    val (a, <!UNUSED_VARIABLE!>b<!>) = c
+    a + 3
+}
+
+fun test3(c: C) {
+    var (<!ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE!>a<!>, <!UNUSED_VARIABLE!>b<!>) = c
+    a = <!UNUSED_VALUE!>3<!>
+}
+
+fun test4(c: C) {
+    var (<!VARIABLE_WITH_REDUNDANT_INITIALIZER!>a<!>, <!UNUSED_VARIABLE!>b<!>) = c
+    a = 3
+    a + 1
+}