[pushed] [gdb/testsuite] Clean up before compilation in gdb.ada/call-no-debug.exp

[Tom Tromey]

Tom> I'm thinking about ways to work around this, but haven't come up with
Tom> anything yet, so for now I've reverted this patch.

The only way I could think of was to have the deletion code be
selective, and not delete gdb.{sum,log}.  Maybe that's overkill though,
considering how few tests really need this treatment.

Tom