Don't check for 4G integer limit on Int32s

Change-Id: I553952888457d98f2d5927528ecd87e53d0be084
x86: Add x86_32 support to CRC32 calculation & use __builtins

This commit adds 32bit CPU support to the CRC32 calculation routines,
and reworks the inline assembly to use compiler __builtin functions
instead.

Change-Id: I79e25f242c5c4451f88ded2bfc953f1dea9ec570
x86: Make `cpudetect' code PIC-aware

Change-Id: Idb12e23b365bd76275cbf139ee493f4542c69a8e