[compiler] Add relocatable pointer constants for wasm memory references.

src/x64/assembler-x64-inl.h

Index: src/x64/assembler-x64-inl.h
diff --git a/src/x64/assembler-x64-inl.h b/src/x64/assembler-x64-inl.h
index 9a0fc7c8f44df7a08ff0fc8ac18625ea2bce4017..58ffc450d277e6a1e1ea1d5f214b102d20d7a3f3 100644
--- a/src/x64/assembler-x64-inl.h
+++ b/src/x64/assembler-x64-inl.h
@@ -326,6 +326,10 @@ Address RelocInfo::target_address() {
   return Assembler::target_address_at(pc_, host_);
 }
 
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Assembler::target_address_at(pc_, host_);
+}
 
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
@@ -364,6 +368,12 @@ void RelocInfo::set_target_address(Address target,
   }
 }
 
+void RelocInfo::update_wasm_memory_reference(
+    Address reference, ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  Assembler::set_target_address_at(isolate_, pc_, host_, reference,
+                                   icache_flush_mode);
+}
 
 Object* RelocInfo::target_object() {
   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);