The file and source text was not being set correctly in the test output.
This change makes the test fixture consistent with the command line
behavior, "-gVS", which was my original intent when I added these tests.
Previously, the type names in the nonsemantic shader debug info would be
"int", "uint", or "float" for all numeric types. This change makes the
correct names such as "int8_t" or "float16_t" get emitted.
