[FIR] Implement FirReturnAllowedChecker

Supported diagnostics:
- RETURN_NOT_ALLOWED
- RETURN_IN_FUNCTION_WITH_EXPRESSION_BODY

compiler/testData/diagnostics/tests/controlStructures/kt799.fir.kt

@@ -12,11 +12,11 @@ fun test() {
     doSmth(if (true) 3 else return, <!TOO_MANY_ARGUMENTS!>1<!>)
 }
 
-val a : Nothing = return 1
+val a : Nothing = <!RETURN_NOT_ALLOWED!>return<!> 1
 
-val b = return 1
+val b = <!RETURN_NOT_ALLOWED!>return<!> 1
 
-val c = doSmth(if (true) 3 else return)
+val c = doSmth(if (true) 3 else <!RETURN_NOT_ALLOWED!>return<!>)
 
 
 fun f(mi: Int = if (true) 0 else return) {}

compiler/testData/diagnostics/tests/controlStructures/localReturnInsidePropertyAccessor.fir.kt

@@ -10,11 +10,11 @@ fun f() = object : ClassData {
 fun g() = object : ClassData {
     init {
         if (true) {
-            return 0
+            <!RETURN_NOT_ALLOWED!>return<!> 0
         }
     }
 
     fun some(): Int {
         return 6
     }
-}
+}

compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_after.fir.kt

@@ -31,7 +31,7 @@ fun testAnnotatedLambdaLabel() =
 
 fun testLambdaMultipleLabels1() =
     lambda1@ lambda2@ {
-        return@lambda1
+        <!RETURN_NOT_ALLOWED!>return@lambda1<!>
     }
 
 fun testLambdaMultipleLabels2() =
@@ -46,7 +46,7 @@ fun testAnonymousFunctionLabel() =
 
 fun testLoopLabelInReturn(xs: List<Int>) {
     L@ for (x in xs) {
-        if (x > 0) return@L
+        if (x > 0) <!RETURN_NOT_ALLOWED!>return@L<!>
     }
 }
 
@@ -59,4 +59,4 @@ fun testHighOrderFunctionCallLabelInReturn() {
     L@ run {
         return@L
     }
-}
+}

compiler/testData/diagnostics/tests/controlStructures/notAFunctionLabel_before.fir.kt

@@ -31,7 +31,7 @@ fun testAnnotatedLambdaLabel() =
 
 fun testLambdaMultipleLabels1() =
     lambda1@ lambda2@ {
-        return@lambda1
+        <!RETURN_NOT_ALLOWED!>return@lambda1<!>
     }
 
 fun testLambdaMultipleLabels2() =
@@ -46,7 +46,7 @@ fun testAnonymousFunctionLabel() =
 
 fun testLoopLabelInReturn(xs: List<Int>) {
     L@ for (x in xs) {
-        if (x > 0) return@L
+        if (x > 0) <!RETURN_NOT_ALLOWED!>return@L<!>
     }
 }
 
@@ -59,4 +59,4 @@ fun testHighOrderFunctionCallLabelInReturn() {
     L@ run {
         return@L
     }
-}
+}