[PATCH] disable var-tracking for math/test-tgmath2.c

[Roland McGrath]

Maybe we should split the code up into more functions or something.  If
there are things like that we can do that improve the compilation speed
without reducing our test coverage, there's no reason not to do them.  But
frankly I'd rather have slow compilation of a test case persist through a
few more GCC versions than do a cheesy hack like this.