Fixed a test failure that occurs when the specified font is not installed.

On systems where 'Liberation Sans' is not installed out-of-the-box
(e.g. Ubuntu Server, OpenSuse Server) it falls back to 'DejaVu Sans',
which makes the GetHashCode_NameDiffers_HashesNotEqual() test fail as
the two font names are now equal. Instead we use 'Arial' and 'Courier New'
which resolve to different fonts on most systems.

Changes licensed under MIT/X11.
[sdb] Add an ExitCode property to VMDeathEvent. Fixes #16113.
[jit] Make the exceptions.cs test suite runnable in mobile.
Mark a few corlib tests as LLVMNotWorking.
[Bug 16186] SqlCommand.BeginExecuteInternal fix

If you use a stored procedure or a prepared statement, with
CommantType.StoredProcedure the ar variable is not set as the result of
onnection.Tds.BeginExecuteProcedure().
Merge pull request #809 from criteo/16186-SqlCommand

[Bug 16186] SqlCommand.BeginExecuteInternal fix
Fix the `nop` opcode on some MIPS-based Loongson CPUs.

After much trouble building Mono in Debian/MIPS, @directhex
narrowed it down to this issue:

https://sourceware.org/ml/binutils/2009-11/msg00387.html

So since some of the 2E and 2F versions of the Loongson CPUs
break with a regular `sll zero, zero, 0` we need to issue an
`or at, at, 0`. This makes sure we don't randomly deadlock or
blow up when the CPU is under heavy load.

Yes, really.
[Bug 16267] SemaphoreSlim.Wait fix when no timeout

See https://bugzilla.xamarin.com/show_bug.cgi?id=16267
[mcs] Import only forwarder kind of exported types.
Fix corlib tests.
[ilasm] Correctly set empty export attributes
Add new test
Bump ikvm-reflection
[runtime] Fix unaligned access in volatile icalls.
[jit] Avoid clearing MONO_INST_FAULT flags when using explicit null checks, LLVM can move the non-faulting loads before the null checks.
[jit] Handle the caller saved D8..D15 register during unwinding on ARM.
Don't register the LLVM SSE intrinsics on arm.
Upgrade the LLVM backend to LLVM e656caccc7dfb5c51c208906f0e176f0973f030f.
Bump expected LLVM version in configure.
Fix the previous commit.