(all patterns): Use GEN_INT instead of gen_rtx to get const_ints.

Avoid double-negative "! NON_*" constructs for clarity.
Pass NULL_PTR as null parameter instead of 0.
(sqrtM2): Patterns are only valid if IEEE FP or -ffast-math.
(sinM2,cosM2): New patterns.
(zero_extract test): New pattern.

From-SVN: r1982