Only check for volatile memcpys in test.

AArch64 handles aggFct's return struct slightly differently, leading
to an extra memcpy. This test is fortunately only concerned about
volatile copies, so we can modify the grep text to filter it.

llvm-svn: 174621

clang/test/CodeGen/volatile.c

@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -emit-llvm < %s -o %t
 // RUN: grep volatile %t | count 28
-// RUN: grep memcpy %t | count 7
+// RUN: grep "memcpy.*, i1 true" %t | count 6
 
 // The number 28 comes from the current codegen for volatile loads;
 // if this number changes, it's not necessarily something wrong, but