u77-test.f failures on some systems

[craig@jcb-sc.com]

>Running target unix
>FAIL: g77.f-torture/execute/u77-test.f execution,  -O0 
>FAIL: g77.f-torture/execute/u77-test.f execution,  -O1 
>FAIL: g77.f-torture/execute/u77-test.f execution,  -O2 
>FAIL: g77.f-torture/execute/u77-test.f execution,  -O2 -fomit-frame-pointer -finline-functions 
>FAIL: g77.f-torture/execute/u77-test.f execution,  -O2 -fomit-frame-pointer -finline-functions -funroll-loops 
>FAIL: g77.f-torture/execute/u77-test.f execution,  -O2 -fomit-frame-pointer -finline-functions -funroll-all-loops 
>FAIL: g77.f-torture/execute/u77-test.f execution,  -Os 

I probably bollixed something in my recent u77-test.f patches.  Could
someone debug the problem on this system, as well as on mips-sgi-irix6.5?
(Though, it might not be me; I added some new test code there, to test
some routines we'd left untested, so perhaps we're unearthing some
latent bugs here.)

        tq vm, (burley)