Use GPRs for mints

runtime/vm/assembler_arm.h

Index: runtime/vm/assembler_arm.h
diff --git a/runtime/vm/assembler_arm.h b/runtime/vm/assembler_arm.h
index 607754bf29551cd055509f544cbb9238d3c59327..19033faf4d3bbea8b2aac179a88f57c0308cedb7 100644
--- a/runtime/vm/assembler_arm.h
+++ b/runtime/vm/assembler_arm.h
@@ -351,8 +351,12 @@ class Assembler : public ValueObject {
 
   void adc(Register rd, Register rn, ShifterOperand so, Condition cond = AL);
 
+  void adcs(Register rd, Register rn, ShifterOperand so, Condition cond = AL);
+
   void sbc(Register rd, Register rn, ShifterOperand so, Condition cond = AL);
 
+  void sbcs(Register rd, Register rn, ShifterOperand so, Condition cond = AL);
+
   void rsc(Register rd, Register rn, ShifterOperand so, Condition cond = AL);
 
   void tst(Register rn, ShifterOperand so, Condition cond = AL);
@@ -694,6 +698,9 @@ class Assembler : public ValueObject {
   void Ror(Register rd, Register rm, Register rs, Condition cond = AL);
   void Rrx(Register rd, Register rm, Condition cond = AL);
 
+  // Fill rd with the sign of rm.
+  void SignFill(Register rd, Register rm);
+
   void Vreciprocalqs(QRegister qd, QRegister qm);
   void VreciprocalSqrtqs(QRegister qd, QRegister qm);
   // If qm must be preserved, then provide a (non-QTMP) temporary.