in which the source code is written. This is controlled by the CSTD
variable, which can have one of the following values:
- "k&r" => -traditional
- "c89" or "c90" => -std=iso9899:1990
- "c94" or "c95" => -std=iso9899:199409
- "c99" => -std=iso9899:1999
The corresponding option is added to CFLAGS regardless of WARNS level.
This also removes -ansi from WARNS level 6, but adds -Wno-long-long to
work around a weird gcc bug (-ansi, which is supposedly equivalent to
-std=iso9899:1990, seems to turn long long warnings off instead of on)
If CSTD is undefined, CFLAGS are unchanged except for the -ansi /
-Wno-long-long change mentioned above for WARNS level 6.
77695b344b