Fix an unused variable warning in non-asserts builds.

llvm-svn: 304778
GitOrigin-RevId: 6c41bb1bdfe248300a817fceafadfc10dd9eec86
diff --git a/unittests/Target/AArch64/InstSizes.cpp b/unittests/Target/AArch64/InstSizes.cpp
index 5ee5e9c..a4bcd682 100644
--- a/unittests/Target/AArch64/InstSizes.cpp
+++ b/unittests/Target/AArch64/InstSizes.cpp
@@ -68,6 +68,7 @@
 
   MachineModuleInfo MMI(TM);
   bool Res = MParser->parseMachineFunctions(*M, MMI);
+  (void)Res;
   assert(!Res && "Couldn't parse MIR functions");
 
   auto F = M->getFunction("sizes");