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

src/compiler/x64/instruction-selector-x64.cc

Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index 731ffde1904904a0b8384f9f0a4ef5a2fdd1dac5..7c2f84d9918bb1b42bcae6fe8ed7c06d81d90ee9 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -22,7 +22,9 @@ class X64OperandGenerator final : public OperandGenerator {
   bool CanBeImmediate(Node* node) {
     switch (node->opcode()) {
       case IrOpcode::kInt32Constant:
+      case IrOpcode::kRelocatableInt32Constant:
         return true;
+      case IrOpcode::kRelocatableInt64Constant:
       case IrOpcode::kInt64Constant: {
         const int64_t value = OpParameter<int64_t>(node);
         return value == static_cast<int64_t>(static_cast<int32_t>(value));