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

src/compiler/instruction.cc

Index: src/compiler/instruction.cc
diff --git a/src/compiler/instruction.cc b/src/compiler/instruction.cc
index 1d28a1bf36cb8024d61ba40eafb525afbd450801..c897157af889133cc0093c587ec31cc245f07c51 100644
--- a/src/compiler/instruction.cc
+++ b/src/compiler/instruction.cc
@@ -504,6 +504,14 @@ std::ostream& operator<<(std::ostream& os,
 
 Constant::Constant(int32_t v) : type_(kInt32), value_(v) {}
 
+Constant::Constant(RelocatablePtrConstantInfo info)
+#ifdef V8_HOST_ARCH_32_BIT
+    : type_(kInt32), value_(info.value()), rmode_(info.rmode()) {
+}
+#else
+    : type_(kInt64), value_(info.value()), rmode_(info.rmode()) {
+}
+#endif
 
 std::ostream& operator<<(std::ostream& os, const Constant& constant) {
   switch (constant.type()) {