Add struct keyword before _Unwind_Context.

In the C programming language, we have to add the
"struct" keyword.  Otherwise, the compiler will
emit error message.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164665 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Headers/unwind.h b/lib/Headers/unwind.h
index a065920..6520b83 100644
--- a/lib/Headers/unwind.h
+++ b/lib/Headers/unwind.h
@@ -100,7 +100,7 @@
   _UVRSR_FAILED = 2  
 } _Unwind_VRS_Result; 
 
-_Unwind_VRS_Result _Unwind_VRS_Get(_Unwind_Context *context,
+_Unwind_VRS_Result _Unwind_VRS_Get(struct _Unwind_Context *context,
   _Unwind_VRS_RegClass regclass,
   uint32_t regno,
   _Unwind_VRS_DataRepresentation representation,
diff --git a/test/Headers/unwind.c b/test/Headers/unwind.c
new file mode 100644
index 0000000..2aec9d4
--- /dev/null
+++ b/test/Headers/unwind.c
@@ -0,0 +1,6 @@
+// RUN: %clang -target arm-unknown-linux-gnueabi %s -fsyntax-only -o -
+// RUN: %clang -target i686-unknown-linux %s -fsyntax-only -o -
+
+#include "unwind.h"
+// CHECK-NOT: error
+// CHECK-NOT: warning