[wasm] Refactor call site patching

src/wasm/leb-helper.h

 // Copyright 2016 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_LEB_HELPER_H_
 #define V8_WASM_LEB_HELPER_H_
 
+#include <cstddef>  // size_t
+#include <cstdint>  // int32_t, ...
+
+#include "src/base/logging.h"
+
 namespace v8 {
 namespace internal {
 namespace wasm {
 
 static const size_t kPaddedVarInt32Size = 5;
 static const size_t kMaxVarInt32Size = 5;
 
 class LEBHelper {
  public:
   // Write a 32-bit unsigned LEB to {dest}, updating {dest} to point after
@@ skipping 100 matching lines @@
         val >>= 7;
       }
     } else {
       while ((val >> 6) != -1) {
         size++;
         val >>= 7;
       }
     }
     return size;
   }
+
+  static inline uint32_t read_u32v(const uint8_t* src) {
+    return read_u32v(&src);
+  }
+
+  static inline uint32_t read_u32v(const uint8_t** src) {
+    uint32_t result = 0;
+    int shift = 0;
+    uint8_t b;
+    do {
+      b = *((*src)++);
+      DCHECK_GE(28, shift);
+      result = result | (static_cast<uint32_t>(b & 0x7F) << shift);
+      shift += 7;
+    } while ((b & 0x80) != 0);
+    return result;
+  }
 };
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_LEB_HELPER_H_