(gles2n64) Clean up old rubbish NEON checking code
(ARM NEON) Have to include header with prototype for performance_counter
callback
Revert "default values if FE doesn't support core options (solves 0x0 viewport issue)" - this crashes x86 32bit Linux - if a proper fixed revision can be
resubmitted and is verified to work on x86 32bit Linux then it can be re-merged

This reverts commit 2083a88fe05f016e86962a695f5e3b583ec0f6aa.