[wasm] Encode immediates to Load and Store as varint.

src/wasm/wasm-opcodes.h

Index: src/wasm/wasm-opcodes.h
diff --git a/src/wasm/wasm-opcodes.h b/src/wasm/wasm-opcodes.h
index fdca7370809034bb0467177d57a472442666bd02..f7184652568014b29aab9055d175c241b7eca7e9 100644
--- a/src/wasm/wasm-opcodes.h
+++ b/src/wasm/wasm-opcodes.h
@@ -46,25 +46,6 @@ const LocalType kAstF64 = MachineRepresentation::kFloat64;
 // We use kTagged here because kNone is already used by kAstStmt.
 const LocalType kAstEnd = MachineRepresentation::kTagged;
 
-// Functionality related to encoding memory accesses.
-struct MemoryAccess {
-  // Atomicity annotations for access to the memory and globals.
-  enum Atomicity {
-    kNone = 0,        // non-atomic
-    kSequential = 1,  // sequential consistency
-    kAcquire = 2,     // acquire semantics
-    kRelease = 3      // release semantics
-  };
-
-  // Alignment annotations for memory accesses.
-  enum Alignment { kAligned = 0, kUnaligned = 1 };
-
-  // Bitfields for the various annotations for memory accesses.
-  typedef BitField<Alignment, 7, 1> AlignmentField;
-  typedef BitField<Atomicity, 5, 2> AtomicityField;
-  typedef BitField<bool, 4, 1> OffsetField;
-};
-
 typedef Signature<LocalType> FunctionSig;
 std::ostream& operator<<(std::ostream& os, const FunctionSig& function);
 
@@ -448,10 +429,6 @@ class WasmOpcodes {
     }
   }
 
-  static byte LoadStoreAccessOf(bool with_offset) {
-    return MemoryAccess::OffsetField::encode(with_offset);
-  }
-
   static char ShortNameOf(LocalType type) {
     switch (type) {
       case kAstI32: