[wasm][eh] Misc fixes found by local fuzzing

- Add missing EnsureStackSpace before unpacking the exception (decoder)
- Pop current catch when delegating to the caller (graph builder)
- Mark throw opcode as unconditional jump

R=clemensb@chromium.org

Bug: v8:8091, v8:11449
Change-Id: I702f6a99581476e77d254e2ea91f9c463ceed444
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2692688
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72737}

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

@@ -2525,6 +2525,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     stack_end_ = stack_ + c->stack_depth;
     c->reachability = control_at(1)->innerReachability();
     const WasmExceptionSig* sig = imm.exception->sig;
+    EnsureStackSpace(static_cast<int>(sig->parameter_count()));
     for (size_t i = 0, e = sig->parameter_count(); i < e; ++i) {
       Push(sig->GetParam(i));
     }

src/wasm/graph-builder-interface.cc

@@ -768,6 +768,7 @@ class WasmGraphBuildingInterface {
       if (depth == decoder->control_depth() - 1) {
         builder_->Rethrow(block->try_info->exception);
         builder_->TerminateThrow(effect(), control());
+        current_catch_ = block->previous_catch;
         return;
       }
       DCHECK(decoder->control_at(depth)->is_try());
@@ -1102,6 +1103,7 @@ class WasmGraphBuildingInterface {
   TFNode* control() { return builder_->control(); }
 
   TryInfo* current_try_info(FullDecoder* decoder) {
+    DCHECK_LT(current_catch_, decoder->control_depth());
     return decoder->control_at(decoder->control_depth() - 1 - current_catch_)
         ->try_info;
   }

src/wasm/wasm-opcodes-inl.h

@@ -504,6 +504,8 @@ constexpr bool WasmOpcodes::IsUnconditionalJump(WasmOpcode opcode) {
     case kExprReturn:
     case kExprReturnCall:
     case kExprReturnCallIndirect:
+    case kExprThrow:
+    case kExprRethrow:
       return true;
     default:
       return false;