[asm.js] [wasm] Store function start position for stack check

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 7b1547e429ec805f7ff277456128c074326a13e2..3258f78d50085df3c70788d0731451e62b58be47 100644
--- a/src/wasm/wasm-module-builder.h
+++ b/src/wasm/wasm-module-builder.h
@@ -135,6 +135,7 @@ class V8_EXPORT_PRIVATE WasmFunctionBuilder : public ZoneObject {
   void ExportAs(Vector<const char> name);
   void SetName(Vector<const char> name);
   void AddAsmWasmOffset(int call_position, int to_number_position);
+  void SetAsmFunctionStartPosition(int position);
 
   void WriteSignature(ZoneBuffer& buffer) const;
   void WriteExports(ZoneBuffer& buffer) const;
@@ -171,6 +172,7 @@ class V8_EXPORT_PRIVATE WasmFunctionBuilder : public ZoneObject {
   ZoneBuffer asm_offsets_;
   uint32_t last_asm_byte_offset_ = 0;
   uint32_t last_asm_source_position_ = 0;
+  uint32_t asm_func_start_source_position_ = 0;
 };
 
 class WasmTemporary {