This was a copy-paste screwup, where the first line of the copyright had the company name was updated, but the company name mid way though was not.
Add copyright headers to build files and scripts. Simplifies automated scanning for bad license headers.
Now that the HLSL source files are part of the `glslang` target (#2271), it makes sense for these to sit in the `glslang` directory. Changed the case of the directory from `hlsl` to `HLSL` to better match the sibling directories.
