ARM/ARM64: Fix smashed CODE_REG in intrinsics with InvokeMathCFunctionInstrs.

runtime/vm/intrinsifier_x64.cc

Index: runtime/vm/intrinsifier_x64.cc
diff --git a/runtime/vm/intrinsifier_x64.cc b/runtime/vm/intrinsifier_x64.cc
index 58f096d3fdb95f1ed0b3250a61e6f3517936c496..5ac5d39bb4d64966a82505077b396e69639e1283 100644
--- a/runtime/vm/intrinsifier_x64.cc
+++ b/runtime/vm/intrinsifier_x64.cc
@@ -32,15 +32,26 @@ namespace dart {
 intptr_t Intrinsifier::ParameterSlotFromSp() { return 0; }
 
 
+static bool IsABIPreservedRegister(Register reg) {
+  return ((1 << reg) & CallingConventions::kCalleeSaveCpuRegisters) != 0;
+}
+
+
 void Intrinsifier::IntrinsicCallPrologue(Assembler* assembler) {
+  ASSERT(IsABIPreservedRegister(CODE_REG));
+  ASSERT(!IsABIPreservedRegister(ARGS_DESC_REG));
+  ASSERT(IsABIPreservedRegister(CALLEE_SAVED_TEMP));
+  ASSERT(CALLEE_SAVED_TEMP != CODE_REG);
+  ASSERT(CALLEE_SAVED_TEMP != ARGS_DESC_REG);
+
   assembler->Comment("IntrinsicCallPrologue");
-  assembler->movq(CALLEE_SAVED_TEMP, R10);
+  assembler->movq(CALLEE_SAVED_TEMP, ARGS_DESC_REG);
 }
 
 
 void Intrinsifier::IntrinsicCallEpilogue(Assembler* assembler) {
   assembler->Comment("IntrinsicCallEpilogue");
-  assembler->movq(R10, CALLEE_SAVED_TEMP);
+  assembler->movq(ARGS_DESC_REG, CALLEE_SAVED_TEMP);
 }