Force C89 for c-index-test.c

MSVC supports only C89, so it is important to keep c-index-test.c
buildable with C89.  However, Clang defaults to C99, so while building
Clang with Clang one can introduce C99 constructs into c-index-test.c
without noticing.

Thanks to Nakamura Takumi for helping with MSVC bits.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167561 91177308-0d34-0410-b5e6-96231b3b80d8

tools/c-index-test/CMakeLists.txt

@@ -7,6 +7,13 @@ add_clang_executable(c-index-test
   c-index-test.c
   )
 
+if(NOT MSVC)
+  set_property(
+    SOURCE c-index-test.c
+    PROPERTY COMPILE_FLAGS "-std=c89"
+    )
+endif()
+
 target_link_libraries(c-index-test
   libclang
   )