[wasm] Introduce EmitVarInt and EmitWithVarInt

src/wasm/wasm-module-builder.h

Index: src/wasm/wasm-module-builder.h
diff --git a/src/wasm/wasm-module-builder.h b/src/wasm/wasm-module-builder.h
index 61aecdcdba80b60a23021c4c27036b55ab814a77..c6903cd95377c49626fdb663fdb86e38fedf00c3 100644
--- a/src/wasm/wasm-module-builder.h
+++ b/src/wasm/wasm-module-builder.h
@@ -121,6 +121,7 @@ class V8_EXPORT_PRIVATE WasmFunctionBuilder : public ZoneObject {
   // Building methods.
   void SetSignature(FunctionSig* sig);
   uint32_t AddLocal(ValueType type);
+  void EmitVarInt(int32_t val);
   void EmitVarUint(uint32_t val);
   void EmitCode(const byte* code, uint32_t code_size);
   void Emit(WasmOpcode opcode);
@@ -130,6 +131,7 @@ class V8_EXPORT_PRIVATE WasmFunctionBuilder : public ZoneObject {
   void EmitI32Const(int32_t val);
   void EmitWithU8(WasmOpcode opcode, const byte immediate);
   void EmitWithU8U8(WasmOpcode opcode, const byte imm1, const byte imm2);
+  void EmitWithVarInt(WasmOpcode opcode, int32_t immediate);
   void EmitWithVarUint(WasmOpcode opcode, uint32_t immediate);
   void EmitDirectCallIndex(uint32_t index);
   void ExportAs(Vector<const char> name);