[wasm] Rework encoding of local declarations.

src/wasm/encoder.h

Index: src/wasm/encoder.h
diff --git a/src/wasm/encoder.h b/src/wasm/encoder.h
index 1afedcb9d6dd4a8174f165a92d461e21da3e56f5..cf6a2b667b38e889dba125eebe59938525f331ba 100644
--- a/src/wasm/encoder.h
+++ b/src/wasm/encoder.h
@@ -10,6 +10,7 @@
 
 #include "src/base/smart-pointers.h"
 
+#include "src/wasm/wasm-macro-gen.h"
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-opcodes.h"
 #include "src/wasm/wasm-result.h"
@@ -23,6 +24,9 @@ class WasmModuleBuilder;
 class WasmFunctionEncoder : public ZoneObject {
  public:
   uint32_t HeaderSize() const;
+  uint32_t LocalDeclSize() const {
+    return static_cast<uint32_t>(local_decls_.Size());
+  }
   uint32_t BodySize() const;
   uint32_t NameSize() const;
   void Serialize(byte* buffer, byte** header, byte** body) const;
@@ -33,20 +37,12 @@ class WasmFunctionEncoder : public ZoneObject {
   friend class WasmFunctionBuilder;
   uint16_t signature_index_;
   ZoneVector<LocalType> params_;
-  uint16_t local_i32_count_;
-  uint16_t local_i64_count_;
-  uint16_t local_f32_count_;
-  uint16_t local_f64_count_;
+  LocalDeclEncoder local_decls_;
   bool exported_;
   bool external_;
   ZoneVector<uint8_t> body_;
   ZoneVector<char> name_;
 
-  bool HasLocals() const {
-    return (local_i32_count_ + local_i64_count_ + local_f32_count_ +
-            local_f64_count_) > 0;
-  }
-
   bool HasName() const { return (exported_ || external_) && name_.size() > 0; }
 };