Add a prefix to the existing test to prepare for more tests of other
backtrace behavior.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@142119 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Misc/macro-backtrace.c b/test/Misc/macro-backtrace.c
index c5fde78..819ec93 100644
--- a/test/Misc/macro-backtrace.c
+++ b/test/Misc/macro-backtrace.c
@@ -16,18 +16,19 @@
 
 void f(int *ip, float *fp) {
   if (M12(ip, fp)) { }
-  // RUN: %clang_cc1 -fsyntax-only -fmacro-backtrace-limit 5 %s 2>&1 | FileCheck %s
-  // CHECK: macro-backtrace.c:18:7: warning: comparison of distinct pointer types ('int *' and 'float *')
-  // CHECK: if (M12(ip, fp)) { }
-  // CHECK: macro-backtrace.c:15:19: note: expanded from:
-  // CHECK: #define M12(A, B) M11(A, B)
-  // CHECK: macro-backtrace.c:14:19: note: expanded from:
-  // CHECK: #define M11(A, B) M10(A, B)
-  // CHECK: note: (skipping 7 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
-  // CHECK: macro-backtrace.c:6:18: note: expanded from:
-  // CHECK: #define M3(A, B) M2(A, B)
-  // CHECK: macro-backtrace.c:5:18: note: expanded from:
-  // CHECK: #define M2(A, B) M1(A, B)
-  // CHECK: macro-backtrace.c:4:23: note: expanded from:
-  // CHECK: #define M1(A, B) ((A) < (B))
+  // RUN: %clang_cc1 -fsyntax-only -fmacro-backtrace-limit 5 %s 2>&1 \
+  // RUN:   | FileCheck %s -check-prefix=CHECK-LIMIT
+  // CHECK-LIMIT: macro-backtrace.c:18:7: warning: comparison of distinct pointer types ('int *' and 'float *')
+  // CHECK-LIMIT: if (M12(ip, fp)) { }
+  // CHECK-LIMIT: macro-backtrace.c:15:19: note: expanded from:
+  // CHECK-LIMIT: #define M12(A, B) M11(A, B)
+  // CHECK-LIMIT: macro-backtrace.c:14:19: note: expanded from:
+  // CHECK-LIMIT: #define M11(A, B) M10(A, B)
+  // CHECK-LIMIT: note: (skipping 7 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
+  // CHECK-LIMIT: macro-backtrace.c:6:18: note: expanded from:
+  // CHECK-LIMIT: #define M3(A, B) M2(A, B)
+  // CHECK-LIMIT: macro-backtrace.c:5:18: note: expanded from:
+  // CHECK-LIMIT: #define M2(A, B) M1(A, B)
+  // CHECK-LIMIT: macro-backtrace.c:4:23: note: expanded from:
+  // CHECK-LIMIT: #define M1(A, B) ((A) < (B))
 }