[Analysis API FIR] fix KtSymbol creation for _ destructuring parameter

We need to have a corresponding declaration in the FIR tree,
so we can create a symbol for it

^KT-60904 fixed
^KT-60904 fixed

compiler/fir/raw-fir/psi2fir/testData/rawBuilder/expressions/destructuring.txt

@@ -34,5 +34,6 @@ FILE: destructuring.kt
     public? final? fun bar(some: Some): R|kotlin/Unit| {
         lval <destruct>: <implicit> = some#
         lval a: <implicit> = R|<local>/<destruct>|.component1#()
+        lval <unused var>: <implicit> = R|<local>/<destruct>|.component2#()
         lval _: <implicit> = R|<local>/<destruct>|.component3#()
     }