[wasm] Remove TFBuilder typedef

It's rarely used, so just using {compiler::WasmGraphBuilder} directly
is easier to understand and does not add much to the code length.

R=titzer@chromium.org

Bug: v8:8238
Change-Id: I8eafaac59295047a8540ebe256f00dff61ddae82
Reviewed-on: https://chromium-review.googlesource.com/c/1276426Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56571}

src/wasm/function-body-decoder.cc

@@ -82,7 +82,8 @@ class WasmGraphBuildingInterface {
     int32_t previous_catch;  // previous Control (on the stack) with a catch.
   };
 
-  explicit WasmGraphBuildingInterface(TFBuilder* builder) : builder_(builder) {}
+  explicit WasmGraphBuildingInterface(compiler::WasmGraphBuilder* builder)
+      : builder_(builder) {}
 
   void StartFunction(FullDecoder* decoder) {
     SsaEnv* ssa_env =
@@ -499,7 +500,7 @@ class WasmGraphBuildingInterface {
 
  private:
   SsaEnv* ssa_env_;
-  TFBuilder* builder_;
+  compiler::WasmGraphBuilder* builder_;
   uint32_t current_catch_ = kNullCatch;
 
   TryInfo* current_try_info(FullDecoder* decoder) {
@@ -853,7 +854,8 @@ DecodeResult VerifyWasmCode(AccountingAllocator* allocator,
 
 DecodeResult BuildTFGraph(AccountingAllocator* allocator,
                           const WasmFeatures& enabled,
-                          const wasm::WasmModule* module, TFBuilder* builder,
+                          const wasm::WasmModule* module,
+                          compiler::WasmGraphBuilder* builder,
                           WasmFeatures* detected, FunctionBody& body,
                           compiler::NodeOriginTable* node_origins) {
   Zone zone(allocator, ZONE_NAME);

src/wasm/function-body-decoder.h

@@ -28,8 +28,6 @@ namespace wasm {
 struct WasmModule;  // forward declaration of module interface.
 struct WasmFeatures;
 
-typedef compiler::WasmGraphBuilder TFBuilder;
-
 // A wrapper around the signature and bytes of a function.
 struct FunctionBody {
   FunctionSig* sig;   // function signature
@@ -50,8 +48,8 @@ V8_EXPORT_PRIVATE DecodeResult VerifyWasmCode(AccountingAllocator* allocator,
 
 DecodeResult BuildTFGraph(AccountingAllocator* allocator,
                           const WasmFeatures& enabled, const WasmModule* module,
-                          TFBuilder* builder, WasmFeatures* detected,
-                          FunctionBody& body,
+                          compiler::WasmGraphBuilder* builder,
+                          WasmFeatures* detected, FunctionBody& body,
                           compiler::NodeOriginTable* node_origins);
 enum PrintLocals { kPrintLocals, kOmitLocals };
 V8_EXPORT_PRIVATE