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.

tests2/54_goto.c

@@ -0,0 +1,56 @@
+#include <stdio.h>
+
+void fred()
+{
+   printf("In fred()\n");
+   goto done;
+   printf("In middle\n");
+done:
+   printf("At end\n");
+}
+
+void joe()
+{
+   int b = 5678;
+
+   printf("In joe()\n");
+
+   {
+      int c = 1234;
+      printf("c = %d\n", c);
+      goto outer;
+      printf("uh-oh\n");
+   }
+
+outer:    
+
+   printf("done\n");
+}
+
+void henry()
+{
+   int a;
+
+   printf("In henry()\n");
+   goto inner;
+
+   {
+      int b;
+inner:    
+      b = 1234;
+      printf("b = %d\n", b);
+   }
+
+   printf("done\n");
+}
+
+int main()
+{
+   fred();
+   joe();
+   henry();
+
+   return 0;
+}
+
+/* vim: set expandtab ts=4 sw=3 sts=3 tw=80 :*/