Work around Intel's failings with with buffer_storage
BannerLoaderWii: Removed #if 0'd code.
FileHandlerARC: Remove FileHandlerARC.
Merge pull request #972 from Sonicadvance1/fix-intel-windows

Work around Intel's failings with buffer_storage
Merge pull request #980 from rohit-n/remove-dead-code

Remove dead code.
JIT: fix branch merging with bclr
Merge pull request #984 from FioraAeterna/fixmergedbclr

JIT: fix branch merging with bclr
Rename Log2 and add IsPow2 to MathUtils for future use

Also remove unused pow2/pow2f functions.
JIT64: optimize multiplication by immediate constants

Factor out common code and handle a few more common cases.
JIT64: optimize rlwinmx/rlwinix and friends

Take advantage of movzx as a replacement for anding with 0xff or 0xffff, and
abuse loads from the register cache to save ops.
JIT64: Optimize cmpXX

Use TEST instead of CMP if we're comparing against 0 (rather common), and
optimize the case of immediate compares further.
JIT64: optimize sign/zero-extend

Also remove some comments that no longer apply since x86_32 was dropped.
JIT64: avoid using LEA for adds when not necessary
JIT64: use LEA for the "a = b + imm" case of addi
JIT64: use xor instead of mov for loading a zero regcache immediate
JIT64: tweak srwx/slwx BindToRegister arguments

Register B gets immediately moved into the shift register, so even if a == b
it doesn't need to be loaded.
JIT64: Optimize carry handling

Carries are rather common and unpredictable, so do them branchlessly wherever
we can.
JIT64: optimize some special cases of srawix

Shift by 31 and 1, both of which are pretty common, can be done in a few less
instructions. Tested with a hwtest.
JIT64: support merged branching for rlwinmx, too

Not quite as common a branch instruction as cmpwi, but close.