Don't use an explicit s0 in ClampDoubleToUint8.

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index 45dd80ffb738b887e126bf70cc1c748d68235602..857c2bf7706488a87c9ccd713f25454c40c56e85 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -3647,8 +3647,8 @@ void MacroAssembler::ClampDoubleToUint8(Register result_reg,
   bind(&in_bounds);
   Vmov(temp_double_reg, 0.5);
   vadd(temp_double_reg, input_reg, temp_double_reg);
-  vcvt_u32_f64(s0, temp_double_reg);
-  vmov(result_reg, s0);
+  vcvt_u32_f64(temp_double_reg.low(), temp_double_reg);
+  vmov(result_reg, temp_double_reg.low());
   bind(&done);
 }