PA-RISC assembler pack: switch to bve in 64-bit builds.

PR: 3074
Optimize SPARC T4 MONTMUL support.

Improve RSA sing performance by 20-30% by:
- switching from floating-point to integer conditional moves;
- daisy-chaining sqr-sqr-sqr-sqr-sqr-mul sequences;
- using MONTMUL even during powers table setup;
SPARC T4 DES support: fix typo.