Cherry-picked update of Android toolchain and memory barrier implementation for Unity 4.x

Merge branch 'unity-4.5-staging' of https://github.com/Unity-Technologies/mono into unity-4.5-staging

Merge branch 'unity-4.5-staging' of https://github.com/Unity-Technologies/mono into unity-4.5-staging

[corlib] Fixed issue with Console.InputEncoding/OutputEncoding not changing the encoding of the underlying writers and readers.

Managed thread id fix (case 601660)

Altered GetNewManagedId to forward to a _internal method instead of being an icall itself, and marked it as a safecall in the audit list

Implement System.Threading.Thread.GetNewManagedID as an icall rather than in managed code, so that it is not reset by a domain reload.

[amd64] Always emit same single-stepping instructions for OP_SEQ_POINT. Fixes issue where the upper 32-bits of ss_trigger_page could be 0 when MONO_ARCH_NOMAP32BIT was defined and mono would crash on single stepping due to a mismatch between single_step_fault_size and the instructions emitted.

[amd64] Fix incorrect single_step_fault_size for MONO_ARCH_NOMAP32BIT. Fixes crash when single stepping into a breakpoint on OSX 64-bit.

	* mini-amd64.h mini-amd64.c tramp-amd64.c aot-compiler.c: Change the IMT
	register to be the same as the RGCTX register, the two can't be used together on
	the same call.

svn path=/trunk/mono/; revision=159928

Conflicts:
	mono/mini/ChangeLog

Fix random crash on Mavericks 64-bit. Backport slightly modified version of https://github.com/mono/mono/commit/978e4ebbd66b231fa6e4f8b32451b87d447bfcf2 and https://github.com/mono/mono/commit/7c85c560ea935b28c5e8492b1a0f6d5e6fe3c14e

	* IPGlobalProperties.cs: Made Win32_IN6_ADDR verifiable.

svn path=/trunk/mcs/; revision=154208

Conflicts:
	mcs/class/System/System.Net.NetworkInformation/ChangeLog

	* verify.c (mono_generic_param_is_constraint_compatible):
	Handle the case when a variable has a class constraints
	and the target has reference constraint. For example:

	C : string
	T : class

	On the above case, C can satisfy the T constraint.

	Fixes #660685

Conflicts:
	mono/metadata/verify.c

This reverts commit 0ded3104.

cherry pick 'fix stack alignment when resuming from a signal handler in the soft debugger. Fixes #647464.' (case 609901)