ARM64: Enable shorten-64-to-32 warning

src/compiler/arm64/code-generator-arm64.cc

Index: src/compiler/arm64/code-generator-arm64.cc
diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index 01de1b0735c51a904da05aa06a52866f3227573c..b32a53b9cb09931405d5e7e0fa5008da8170ca38 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -337,7 +337,8 @@ Condition FlagsConditionToCondition(FlagsCondition condition) {
       __ asm_instr(i.OutputRegister##width(), i.InputRegister##width(0),       \
                    i.InputRegister##width(1));                                 \
     } else {                                                                   \
-      int64_t imm = i.InputOperand##width(1).immediate().value();              \
+      int imm =                                                                \
+          static_cast<int>(i.InputOperand##width(1).immediate().value());      \
       __ asm_instr(i.OutputRegister##width(), i.InputRegister##width(0), imm); \
     }                                                                          \
   } while (0)