Turned off -W and -Winline so that the warnings that should be fixed for
2.2 are more obvious. -Winline is unimportant, but -W gives thousands
of warnings for comparisions. Turning off -W also loses warnings for:

• auto variables clobbered by longjmp. Not much of a problem in the kernel.
• functions returning without a value. I don't like losing this.
• an expression statement or the left side of a comma operand contains no side effects. Turning this off also stops warnings for the low quality debugging macros in gsc.c and lpt.c.

Should be in 2.2.