[FIR] Fix local variable tests.

- Mangle names for extension receivers in lambdas
 - Correctly mark anonymous variables and variables for arguments
   for destructuring declaration.

There is one failure remaining which is cause by lambda
type inference differences that leads to FIR having an explicit
return from the lambda whereas old frontend leads to an implicit
return. This difference is visible in debug stepping that the
local variables tests do because the implicit return has the line
number of the closing brace of the lambda. This change adds an
IrText test to make the difference clear.

compiler/testData/ir/irText/classes/initValInLambda.fir.ir.txt

@@ -22,7 +22,7 @@ FILE fqName:<root> fileName:/initValInLambda.kt
           $receiver: CONST Int type=kotlin.Int value=1
           block: FUN_EXPR type=kotlin.Function1<kotlin.Int, kotlin.Unit> origin=LAMBDA
             FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> ($receiver:kotlin.Int) returnType:kotlin.Unit
-              $receiver: VALUE_PARAMETER name:<this> type:kotlin.Int
+              $receiver: VALUE_PARAMETER name:$this$run type:kotlin.Int
               BLOCK_BODY
                 SET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:x type:kotlin.Int visibility:private [final]' type=kotlin.Unit origin=null
                   receiver: GET_VAR '<this>: <root>.TestInitValInLambdaCalledOnce declared in <root>.TestInitValInLambdaCalledOnce' type=<root>.TestInitValInLambdaCalledOnce origin=null