[wasm] Avoid redundant {EndControl}

Many callers of {DoReturn} either already call {EndControl}, or pop
the control afterwards, hence we do not need to {EndControl}.
Hence only call {EndControl} when really needed.

R=herhut@chromium.org

Bug: v8:8423
Change-Id: Ie4e7b2dd6918cc0f9619a72d624014222f58a251
Reviewed-on: https://chromium-review.googlesource.com/c/1384085Reviewed-by: Stephan Herhut <herhut@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58359}

src/wasm/function-body-decoder-impl.h

@@ -1895,6 +1895,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
         case kExprReturn: {
           if (!TypeCheckReturn()) break;
           DoReturn();
+          EndControl();
           break;
         }
         case kExprUnreachable: {
@@ -2572,8 +2573,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
             : Vector<Value>{&*(stack_.end() - return_count), return_count};
 
     CALL_INTERFACE_IF_REACHABLE(DoReturn, return_values);
-
-    EndControl();
   }
 
   inline Value* Push(ValueType type) {