Fix unused-variable error on release builds.

TBR=ulan@chromium.org

Review URL: https://codereview.chromium.org/466333006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23279 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

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;
 }