Since AM_INIT_AUTOMAKE calls AC_PROG_AWK, and some configure.ac
scripts call it too, we end up testing for awk multiple times. If
we change NEWLIB_CONFIGURE to require the macro instead, then it
makes sure it's always expanded, but only once.
While we're here, do the same thing with AC_PROG_INSTALL since it
is also called by AM_INIT_AUTOMAKE, although it doesn't currently
result in duplicate configure checks.
This matches what the other GNU toolchain projects have done already.
The generated diff in practice isn't terribly large. This will allow
more use of subdir local.mk includes due to fixes & improvements that
came after the 1.11 release series.
The newlib & libgloss dirs are already generated using autoconf-2.69.
To avoid merging new code and/or accidental regeneration using diff
versions, leverage config/override.m4 to pin to 2.69 exactly. This
matches what gcc/binutils/gdb are already doing.
The README file already says to use autoconf-2.69.
To accomplish this, it's just as simple as adding -I flags to the
top-level config/ dir when running aclocal. This is because the
override.m4 file overrides AC_INIT to first require the specific
autoconf version before calling the real AC_INIT.