HLSL: Halfs are not recognized as a type

[redorav]

The only thing that needs to happen really is that they are recognized and promoted to float.

Per https://msdn.microsoft.com/en-us/library/windows/desktop/bb509646(v=vs.85).aspx

"This data type is provided only for language compatibility. Direct3D 10 shader targets map all half data types to float data types."

However many shaders use half because they are also compiled on other platforms.

[dankbaker]

It process the token I notice, should verify that min16float etc work as well.

[johnkslang]

Moved to issue #362.

[johnkslang]

Note that the h suffix is now supported, so that #define half float etc. works.