Allow GL_TEXTURE_MAX_ANISOTROPY_EXT from sampler object.

Bug b/38257724

Change-Id: I4157ef825ed4ed8f805e9dad35b43bb5780877b6
Reviewed-on: https://swiftshader-review.googlesource.com/9788
Reviewed-by: Nicolas Capens <capn@google.com>
Reviewed-by: Lingfeng Yang <lfy@google.com>
Tested-by: Lingfeng Yang <lfy@google.com>

src/OpenGL/libGLESv2/libGLESv3.cpp

diff --git a/src/OpenGL/libGLESv2/libGLESv3.cpp b/src/OpenGL/libGLESv2/libGLESv3.cpp
index be814f3..adfb48e 100644
--- a/src/OpenGL/libGLESv2/libGLESv3.cpp
+++ b/src/OpenGL/libGLESv2/libGLESv3.cpp
@@ -492,6 +492,7 @@
 	case GL_TEXTURE_MAX_LOD:
 	case GL_TEXTURE_COMPARE_MODE:
 	case GL_TEXTURE_COMPARE_FUNC:
+	case GL_TEXTURE_MAX_ANISOTROPY_EXT:
 		return true;
 	default:
 		return false;