[wasm] Inline Pop methods for performance

This improves validation time by 7-8% and Liftoff compilation time by
2-3% while increasing binary size by ~12kB.

R=mvstanton@chromium.org

Bug: v8:8423
Change-Id: I08961097fb61f4a218522138efe51a9165a7c62b
Reviewed-on: https://chromium-review.googlesource.com/c/1391748Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58486}

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

@@ -2551,7 +2551,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return stack_.data() + old_size;
   }
 
-  Value Pop(int index, ValueType expected) {
+  V8_INLINE Value Pop(int index, ValueType expected) {
     auto val = Pop();
     if (!VALIDATE(val.type == expected || val.type == kWasmVar ||
                   expected == kWasmVar)) {
@@ -2563,7 +2563,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return val;
   }
 
-  Value Pop() {
+  V8_INLINE Value Pop() {
     DCHECK(!control_.empty());
     uint32_t limit = control_.back().stack_depth;
     if (stack_.size() <= limit) {