[wasm] Adding feature to JIT a wasm function at runtime and hook up the compiled code into the indi…

src/wasm/ast-decoder.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_WASM_AST_DECODER_H_
 #define V8_WASM_AST_DECODER_H_
 
 #include "src/signature.h"
 #include "src/wasm/decoder.h"
 #include "src/wasm/wasm-opcodes.h"
@@ skipping 132 matching lines @@
   inline CallImportOperand(Decoder* decoder, const byte* pc) {
     unsigned len1 = 0;
     unsigned len2 = 0;
     arity = decoder->checked_read_u32v(pc, 1, &len1, "argument count");
     index = decoder->checked_read_u32v(pc, 1 + len1, &len2, "import index");
     length = len1 + len2;
     sig = nullptr;
   }
 };
 
+struct JITSingleFunctionOperand {
+  uint32_t sig_index;
+  FunctionSig* sig;
+  unsigned length;
+  inline JITSingleFunctionOperand(Decoder* decoder, const byte* pc) {
+    sig_index = decoder->checked_read_u32v(pc, 1, &length, "signature index");
+    sig = nullptr;
+  }
+};
+
 struct BranchTableOperand {
   uint32_t arity;
   uint32_t table_count;
   const byte* table;
   unsigned length;
   inline BranchTableOperand(Decoder* decoder, const byte* pc) {
     unsigned len1 = 0;
     unsigned len2 = 0;
     arity = decoder->checked_read_u32v(pc, 1, &len1, "argument count");
     table_count =
@@ skipping 169 matching lines @@
   }
 
   bool has_next() { return pc_ < end_; }
 };
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_AST_DECODER_H_