Building release-only for Win32 creates .pc files with d suffix

When building Qt for win32 with "-release" the .pc files generated use a 'd' suffix, like Qt5Cored. Even when using "make release".

After investigating what's going on, it seems that qmake generates the makefiles and prl files for debug and release all the time, even if only release was selected. In both cases the .pc files are generated with the same name. The debug one is generated after the release one and thus overwrites the release one.

I don't know if it would make sense to generate .pc files with the debug suffix for the debug target, or if the order release/debug to generate the files could be reversed or if it's a bug that both variants are built when only release is selected in the Qt configuration.