A64: Handle Smi representation in MathAbs and fix MathPowStub

src/a64/lithium-codegen-a64.cc

Index: src/a64/lithium-codegen-a64.cc
diff --git a/src/a64/lithium-codegen-a64.cc b/src/a64/lithium-codegen-a64.cc
index ad02f5debe7627e3bef36be3516323796a329de4..aeb18d05860e2b13bd2187edb7168fe0e6075431 100644
--- a/src/a64/lithium-codegen-a64.cc
+++ b/src/a64/lithium-codegen-a64.cc
@@ -3525,7 +3525,8 @@ void LCodeGen::DoMathAbsTagged(LMathAbsTagged* instr) {
   DeferredMathAbsTagged* deferred =
       new(zone()) DeferredMathAbsTagged(this, instr);
 
-  ASSERT(instr->hydrogen()->value()->representation().IsTagged());
+  ASSERT(instr->hydrogen()->value()->representation().IsTagged() ||
+         instr->hydrogen()->value()->representation().IsSmi());
   Register input = ToRegister(instr->value());
   Register result_bits = ToRegister(instr->temp3());
   Register result = ToRegister(instr->result());