Generating OS-appropriate mapfiles from a provided SYMBOL_FILE is
apparently required to work with newer ffvpx. Nothing else in our
codebase actually seemed to require it. Also seems to reduce the amount
of console spam I see relating to symbol visibility during the build
process, and I think it even makes libxul.so link a bit faster.
Signed-off-by: athenian200 <athenian200@outlook.com>
Vim control lines were re-introduced or not entirely cleaned up.
This nukes them again.
Removing from the rest of js, caps, chrome, config, devtools, docshell,
image, intl. More to come.
