#975650).
- Fix false positives from cmake which probes for compiler flags without
setting CPPFLAGS; reported and suggested fix by Joao Eriberto Mota Filho
- (Debian Bug #994154).
+ (Debian Bug #994422).
- Properly handle quoted flags; reported by Olek Wojnar (see Debian Bug
#975650 message 45).
- Strip (basic) environment variables before compiler detection to reduce