Add required flags for using the new SwiftOnoneSupport library

[swiftix]

This is a PR related to the following PR: swiftlang/swift#1429
They should be merged in sync, otherwise foundation builds will fail after the mentioned PR is merged.

[phausler]

if this causes a segfault in one of the tests and it is currently working that probably means there is an expectation failure that is not met in your library:

it is worth noting the lines below are incorrect and should not be modified at that point:

from lib/script.py:111

        if Configuration.current.build_mode == Configuration.Debug:
            swift_flags += "-g -Onone "
        elif Configuration.current.build_mode == Configuration.Release:
            swift_flags += "-O "

that modification runs just fine without your changes; can you get me the crash point by attaching lldb?

cd swift-corelibs-foundation
ninja test
LD_LIBRARY_PATH=../build/Ninja-ReleaseAssert/foundation-linux-x86_64/Foundation/:/home/phausler/Public/build/Ninja-ReleaseAssert/xctest-linux-x86_64 ../build/Ninja-ReleaseAssert/lldb-linux-x86_64/bin/lldb ../build/Ninja-ReleaseAssert/foundation-linux-x86_64/TestFoundation/TestFoundation

presuming you built as release mode in the standard layouts

[swiftix]

@phausler Actually, I was wrong. There is no crash anymore. Looks like I fixed it on the Swift side after I tested yesterday. Which means, that we can enable -O for Release, if we want. Or we can continue with foundation.LDFLAGS += ' -lswiftSwiftOnoneSupport '. It is up to you what you prefer for foundation.

[swiftix]

Let me know if you want me to submit the corresponding PR or if you want to commit this one-liner yourself.

[phausler]

I will change the -O for release mode in a follow up

[swiftix]

OK. Should I then just remove the Release related part altogether and have only the change for LDFLAGS in Debug mode?

[swiftix]

Or should I remove the comment about -O which is obsolete by now.

[phausler]

as soon as the corresponding swift commit is merged I will merge this and push corrections for the release builds

[swiftix]

OK. Understood. I'm about to merge the Swift commit now.

[swiftix]

Done.

[swiftix]

With your -O commit, you probably want to remove the
Configuration.current.build_mode == Configuration.Release: block from the build script. It is not needed in -O builds. If you leave it there, it may result in SwiftOnoneSupport being linked and referred even though it is not used by an app or a dylib.

But let's first see that everything builds fine. Once everything is fine, we can remove this if-statement.

[swiftix]

@phausler Thanks for your support!