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.
- This patch uses gdtoa imported from OpenBSD if newlib configure
option "--enable-newlib-use-gdtoa=no" is NOT specified. gdtoa
provides more accurate output and faster conversion than legacy
ldtoa, while it requires more heap memory.