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

runtime/vm/intrinsifier_arm.cc

Index: runtime/vm/intrinsifier_arm.cc
diff --git a/runtime/vm/intrinsifier_arm.cc b/runtime/vm/intrinsifier_arm.cc
index 119fd7aa1f9d73ab536a6b99429b57060eda72fd..e17abcb149f0de61c9058a3553ae74905f279b51 100644
--- a/runtime/vm/intrinsifier_arm.cc
+++ b/runtime/vm/intrinsifier_arm.cc
@@ -33,7 +33,16 @@ namespace dart {
 intptr_t Intrinsifier::ParameterSlotFromSp() { return -1; }
 
 
+static bool IsABIPreservedRegister(Register reg) {
+  return ((1 << reg) & kAbiPreservedCpuRegs) != 0;
+}
+
+
 void Intrinsifier::IntrinsicCallPrologue(Assembler* assembler) {
+  ASSERT(IsABIPreservedRegister(CODE_REG));
+  ASSERT(IsABIPreservedRegister(ARGS_DESC_REG));
+  ASSERT(IsABIPreservedRegister(CALLEE_SAVED_TEMP));
+
   // Save LR by moving it to a callee saved temporary register.
   assembler->Comment("IntrinsicCallPrologue");
   assembler->mov(CALLEE_SAVED_TEMP, Operand(LR));