Further work on the function emulation.

Further work on the function emulation.

This is to work around driver bugs.  We added more functions, and removed some unnecessary ones.  Remove the function group because we have flags for each function now.  Use more macros instead of functions.  Don't emit global precision because that will affect all later code.

ANGLEBUG=196
TEST=build and test on Mac ATI/NVIDIA, fixes the failing webgl glsl conformance tests.
Committed: http://code.google.com/p/angleproject/source/detail?r=754

[zmo, 2011-09-15 23:33:40]

Please review.

[kbr1, 2011-09-16 00:13:04]

LGTM

Thanks for cutting down the set of functions needing workarounds to the minimal
set.

http://codereview.appspot.com/5011053/diff/1/src/compiler/BuiltInFunctionEmul...
File src/compiler/BuiltInFunctionEmulator.cpp (right):

http://codereview.appspot.com/5011053/diff/1/src/compiler/BuiltInFunctionEmul...
src/compiler/BuiltInFunctionEmulator.cpp:13: const char*
kFunctionEmulationVertexSource[] = {
Please add a comment that we use macros here instead of function definitions to
work around more GLSL compiler bugs, in particular on NVIDIA hardware on Mac OS
X. Macros are problematic because if the argument has side-effects they will be
repeatedly evaluated. This is unlikely to show up in real shaders, but is
something to consider.