- sprinkle const
- add a macro (setptr) that cheats const to temporarily NUL terminate strings
remove casts from allocations
- use strdup instead of strlen+strcpy
- use x = malloc(sizeof(*x)) instead of x = malloc(sizeof(type of *x)))
- add -Wcast-qual (and casts through unitptr_t in the two macros we
cheat (xfree, setptr)).
Support POSIX-specified C-style escape sequences "\a" (alarm)
and "\v" (vertical tab) in command line arguments and regular
expressions, further to the support for them in strings added on
Apr 9, 1989. These now no longer match as literal "a" and "v"
characters (as they don't on gawk and mawk).
IOW, lex.c already supported these (lines 390-391 as of 4e343460);
the support needed to be added to b.c and tran.c.
Relevant POSIX reference:
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/awk.html#tag_20_06_13_04
Also remove a redundant semicolon.
Also had to rebase on upstream pull.
git-svn-id: svn+ssh://svn.freebsd.org/base/head@301289 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
