Fix unused-variable error on release builds.

src/arm/assembler-arm.cc

Index: src/arm/assembler-arm.cc
diff --git a/src/arm/assembler-arm.cc b/src/arm/assembler-arm.cc
index e586e5421e9d9e2f2a49c6736bd8d4ea0fab9e68..e7b81cbb171aa5a1d18484e4e45f616aedff99d7 100644
--- a/src/arm/assembler-arm.cc
+++ b/src/arm/assembler-arm.cc
@@ -3176,6 +3176,7 @@ Instr Assembler::PatchShiftImm(Instr instr, int immed) {
   uint32_t immed_8 = 0;
   bool immed_fits = fits_shifter(immed, &rotate_imm, &immed_8, NULL);
   DCHECK(immed_fits);
+  USE(immed_fits);
   return (instr & ~kOff12Mask) | (rotate_imm << 8) | immed_8;
 }