(byte-compile-compatibility): Doc fix.

(byte-compile-compatibility): Doc fix.
(byte-compile-format-warn): New.
(byte-compile-callargs-warn): Use it.
(Format, message, error): Add byte-compile-format-like property.
(byte-compile-maybe-guarded): New.
(byte-compile-if, byte-compile-cond): Use it.
(byte-compile-lambda): Compile interactive forms, just to make
warnings about them.