* Revert "[strip -ST] Disable runtime stack trace dumping on Darwin when asserts are disabled."
This reverts commit 6bc28ff1c9.
* Bring back important fixes from the revert of 6bc28ff1c9.
* Change swift::swift_reportError to only print the backtrace in assert builds (swift::warning prints backtrace always).
This commit disables runtime stack trace dumping via dladdr on Darwin when
asserts are disabled.
This stack trace dumping was added as a way to improve the ability to debug the
compiler for compiler developers. This is all well and good but having such a
feature always enabled prevents us from reducing the size of the swift standard
library by eliminating the swift nlist.
rdar://31372220
Previously, we were using backtrace_symbol and then parsing/modifying its
output. By just using dladdr directly, we have a cleaner and more robust
solution.
rdar://25064742
