Disable inline_asm_direct_symbol_refs if lto was requested.

This fixes link time optimizations with gcc without disabling inline asm.

Fixes ticket #2941.
Map --enable-lto to -ipo when compiling with icc.
Merge remote-tracking branch 'cehoyos/master'

* cehoyos/master:
  Map --enable-lto to -ipo when compiling with icc.
  Disable inline_asm_direct_symbol_refs if lto was requested.

Merged-by: Michael Niedermayer <michaelni@gmx.at>