Compilation and link times in CPU seconds with GCC 7, using precompiled
headers (not including moc, rcc, uic, etc. steps or headersclean):
Before After
Debug -O0 198,1 180,3
Debug -Og 240,7 229,2
Release -O3 267,1 249,2
Release LTO 239,4 229,8
QtCore required a little manual adjusting because some files are
bootstrapped into moc itself and into qmake.
Change-Id: I84e363d735b443cb9beefffd14b8b57c10e7da36
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
