ANGLE's ESSL3 built-in function isnan() implementation just uses HLSL
intrinsic function isnan(). For HLSL intrinsic function isnan() to work
properly, IEEE strictness needs to be enabled for D3D compiler.

This change detects use of isnan() in shaders and passes compiler flag
D3DCOMPILE_IEEE_STRICTNESS whenever isnan is used in shaders. This
change also moves existing workarounds in D3DWorkaroundType to
D3DCompilerWorkarounds.

BUG=angle:927
TEST= dEQP tests
dEQP-GLES3.functional.shaders.builtin_functions.common.isnan.*

Change-Id: I1ce5b1a7a825fdd720a37dc9aeb71320e55162d9
Reviewed-on: https://chromium-review.googlesource.com/255834Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>
Tested-by: Jamie Madill <jmadill@chromium.org>