tests: Added numerous tests.

The tests are taken almost verbatim from the open source project PicoC. It can
be found at https://code.google.com/p/picoc/.

The tests range from very simple/trivial ones to more complicated. My view is
that the more tests the better. Without tests like this I was very reluctant to
make any changes to tcc for the fear of breaking things.

The tests pass on Win32, OSX, Linux x86 and x86_64. One or two tests fail on
each platform due to differences in the runtime library.

tests2/52_unnamed_enum.c

@@ -0,0 +1,27 @@
+#include <stdio.h>
+
+enum fred { a, b, c };
+
+int main()
+{
+   printf("a=%d\n", a);
+   printf("b=%d\n", b);
+   printf("c=%d\n", c);
+
+   enum fred d;
+
+   typedef enum { e, f, g } h;
+   typedef enum { i, j, k } m;
+
+   printf("e=%d\n", e);
+   printf("f=%d\n", f);
+   printf("g=%d\n", g);
+
+   printf("i=%d\n", i);
+   printf("j=%d\n", j);
+   printf("k=%d\n", k);
+
+   return 0;
+}
+
+/* vim: set expandtab ts=4 sw=3 sts=3 tw=80 :*/