LogicalSet/GetData implementation in CallContext
[xbuild]: Provide diagnostic logging of all executed targets.
[xbuild]: Check a <Target>'s "Returns" first, then fall-back to "Outputs".

This fixes a problem with the "Microsoft.Bcl.Build" NuGet package, which
overrides the "GetTargetPath" target in a custom .targets file and uses
"Returns" instead of "Outputs".
Fixed missing pointer conversion tests in sizes.c

Unsigned pointer conversion was not tested at all (looks like a copy & paste mistake)
[sgen] Link unit test programs with all libs.

Should fix the build for monodroid.
[corlib] Update CurrentRegion to work with DefaultThreadCurrentCulture
Remove some more mdb bits.
[corlib] CreateSpecificCulture without exception retry
Unbreak libgc.
Merge pull request #824 from hanswolff/patch-1

Fixed missing pointer conversion tests in sizes.c
Fix a warning on PPC.
Fix more PPC warnings.
Fix a couple of warnings in mini-exceptions.c.
Fix some warnings in mini-amd64.c.
[corlib] Better conversion betwen system locale and CultureInfo. Fixes #15875
Fix some warnings caused by always_inline functions not being marked inline.
Add a dummy assignment to shut GCC up.
Fix some pointer/integer size issues in unwind.c on 32-bit systems.
[xbuild]: Fix the tests.

'TestMessageLogger.Count' should not be used in tests to check for the
number of logged messages because it would also includes diagnostic messages.

Extra diagnostic messages should not be considered an error condition; in
fact, we have too few diagnostic messages, not too many.

Use 'TestMessageLogger.NormalMessageCount' and 'TestMessageLogger.WarningMessageCount'
instead.
Fix some warnings in mini-arm.c.