googletest

cmake: make PDB output directory match that of a static library.

PDB files should be created at the same location as their primary
artifact, which is either static library or a DLL.

On Windows, an artifact location is controlled by:

* RUNTIME_OUTPUT_DIRECTORY is a directory of a DLL artifact.
* ARCHIVE_OUTPUT_DIRECTORY is a directory of a LIB artifact.

A PDB file location is controlled:

* PDB_OUTPUT_DIRECTORY should match a directory of a DLL artifact.
* COMPILE_PDB_OUTPUT_DIRECTORY should match a directory of a LIB artifact.