Vendor import of byacc 20120526

Approved by:	des (mentor, implicit)
Import byacc 20130304
Import byacc version 20130925
Merge byacc 20130925

2 changes:
- Increase default stack-size so that used to be our default stack-size prior byacc import
- fix two loop-limits found by clang 3.3
Change warning level to 6