[AArch64] Removes ARMv8 as a generic target.

Generic flag disables the ability to have backpatching supporting.
Also compiles Dolphin with CRC instructions enabled.
[AArch64] Register cache improvements.
Adds the ability to flush the cache and maintain state.
Adds the BindToRegister ability.
Sorts register usage as callee saved used first, reduces dumping pressure when jumping to external routines/interpreter.
Adds a function to store a register, for use when flushing a register that won't be used during the rest of a block.
[ARM] Adds a ArmCommon folder.

Moves the backpatch flags and struct to a common location for ARM.
I'm sure there will be more things that use this common ARM location in the future.
[AArch64] Removes CODE_SIZE variable.

This is in a global location now which conflicts with this one.
[AArch64] Add an exception exit function with the exit location already in PC.
This will be used with idle skipping later.
[AArch64] Optimization in the dispatcher.

Align our dispatcher to a page so we can jump to it with a ADRP+BR pair instead of ADRP+ADD+BR.
Also make sure to save /all/ of our callee saved registers that we are supposed to save.
Requires PR #1705 prior to merging.
[AArch64] Flush registers from register cache if they won't be used again.

This requires PR #1705 and #1723 prior to merging.
[AArch64] Adds support for BindToRegister to the integer instructions.

This requires PR #1723 prior to merging.
[AArch64] Add partial support for cmp* instructions.

This support is as far as ARMv7's support for these instructions.
Requires PR #1728 prior to merging.
Update Outdated Google Code References
VideoLoader: remove VAT_*_FRACBITS

They are used to remove the flush amounts, but as we don't
flush anymore on vertex loader changes (only on native
vertex format right now), this optimization is now unneeded.

This will allow us to hard code the frac factors within the
vertex loaders.
VertexLoaderUid: remove operator<

Not needed for unordered map.
VideoCommon: Move NativeVertexFormat cache to VertexLoaderManager
VertexLoader: remove inlined getters

They just blow up the code.
VideoCommon: split VertexLoaderBase from VertexLoader
VertexLoader: Add a test loader which compares two vertex loaders
VertexLoader: Add a VertexLoader pointer to each function call
VertexLoader: Merge dummy functions
VertexLoader: Skip vertices with position index = -1
AR: Fix Memory Copy Without Pointer Support

Fix a bug when using AR codes with "Memory Copy Without Pointer Support"
code type which would write more data than it should.