[mono][jit] Partially implemented logical immediates on arm64

[jandupej]

This implements a subset of https://developer.arm.com/documentation/ddi0596/2020-12/Base-Instructions/AND--immediate---Bitwise-AND--immediate-- (incl. ands, eor, orr). If the immediate value can be expressed as (1<<n) - 1, the new codegen is used. Although this covers only a few of the cases supported by the instruction, the instances where we are trying to mask away some of the upper bits seem prevalent (in our codebase) and are handled here.

E.g. clamping the shift amount in long shifts:

0000000000000018        mov     x30, #0x3f
000000000000001c        and     w1, w0, w30

becomes

0000000000000018        and     w1, w0, #0x3f

EDIT: The recognized bit pattern is now expanded to 0*1+0*. A plain-ish HelloWorld build revealed almost 400 instances of this pattern.

[lambdageek]

ctz is for 32-bit inputs

[lambdageek]

Can we put this in a header in mono/utils (or in minipal) so we can use it in more places

[jandupej]

CI failures are not related. Merging.