Also, restructure the `CHECK:` lines for the `-emit-tbd` test. The number of
columns in the `.tbd` file appears to be variable, so we can't assume a layout
for the symbols in the YAML.
Build swift-frontend as the primary Swift binary, and have
swift/swiftc/etc. symlink over to it. This is a step toward allowing
swift-driver to replace the swift and swiftc binaries.
The `-force-single-frontend-invocation` flag predates WMO and is now an
alias for `-whole-module-optimization`. We should use the latter and let
the former fade into history.
Clang 8 or 9 seems to have changed from EXE to exe. Allow both
capitalizations (which is not important in Windows) as a workaround.
Maybe in the future we can remove the uppercase option.
Commit to a command line option spelling so that build systems can
start testing it. I deliberately picked one of the longer names we
were considering because we can always decide to add a shorter alias,
but can't decide a shorter name was too generic.
Like the other supplementary output flags,
-emit-parseable-module-interface-path will emit a .swiftinterface file
to a particular path, while -emit-parseable-module-interface will put
it next to the main output (the one specified with -o).
rdar://problem/43776945
