Add a very simple test for the pre-processor.

Validate desired test cases by ensuring the output of glcpp matches
the output of the gcc preprocessor, (ignoring any lines of the gcc
output beginning with '#').

Only one test case so far with a trivial #define.

1 files changed, 2 insertions, 0 deletions

diff --git a/tests/001-define.c b/tests/001-define.c
new file mode 100644
index 0000000000..cbf2fee0e7
--- /dev/null
+++ b/tests/001-define.c
@@ -0,0 +1,2 @@
+#define foo 1
+foo