[arm] Refactor arm disassembler for special condition

The SpecialValue field used in the disassembler covers too wide a range,
this causes some duplication in the disassembler of instructions like
mov, since the SpecialValue includes a bit used for the immediate.

Attempt to refactor and follow the decoding guide given in the
architecture manual [0], F4.1 A32 instruction set encoding, with the
eventual goal for removing the duplicated instruction disassembly.

[0] ARM DDI 0487F.b ARMv8 A32 instruction set

Bug: v8:10933
Change-Id: Iddf4df317f9a5b29be2544ad2f9f93180e9bcdfc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2497395
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70775}

test/cctest/test-disasm-arm.cc

@@ -1275,6 +1275,10 @@ TEST(Neon) {
               "f3b6f100       vuzp.16 d15, d0");
       COMPARE(vuzp(Neon16, q15, q0),
               "f3f6e140       vuzp.16 q15, q0");
+      COMPARE(vrev16(Neon8, q15, q0),
+              "f3f0e140       vrev16.8 q15, q0");
+      COMPARE(vrev32(Neon8, q15, q0),
+              "f3f0e0c0       vrev32.8 q15, q0");
       COMPARE(vrev64(Neon8, q15, q0),
               "f3f0e040       vrev64.8 q15, q0");
       COMPARE(vtrn(Neon16, d15, d0),