Add support to clightgen for generating Csyntax AST as .v files

As proposed in #404.

This is presented as a new option `-clight` to the existing `clightgen` tool.

Revise clightgen testing to test the Csyntax output in addition to
the Clight output.

1 files changed, 13 insertions, 0 deletions

diff --git a/test/export/bitfields.c b/test/export/bitfields.c
new file mode 100644
index 00000000..34f6a686
--- /dev/null
+++ b/test/export/bitfields.c
@@ -0,0 +1,13 @@
+struct s {
+  int a: 10;
+  char : 6;
+  _Bool b : 1;
+  int : 0;
+  short c: 7;
+};
+
+int f(void)
+{
+  struct s x = { -1, 1, 2 };
+  return x.a + x.b + x.c;
+}