Disable optimizer for 32bit PA-RISC builds on HP-UX

Disable optimizer for 32bit PA-RISC builds on HP-UX

The (ANSI) C compiler fails to compile precompiled (.i) files when both
-g and -O (all +O1 and above) are given. When -g is requested, -O, +O,
and +Onolimit are removed from optimize flags

This #fail does not occur with the newer aCC compiler B3910B, which is
also used on HP-UX on Itanium.

The check/modification has to be done as late as possible, as the other
options, like -Duse64bitall and -DDEBUGING, will modify the variables
that need to be checked after hints/hpux.sh has been dealt with.