This reverts commit 3ad101f5.

Reason for revert: Broken Android Arm64 debug builder - https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Android%20Arm64%20-%20debug%20builder/3089

Original change's description:
> [assembler] Split out CPUFeatures into its own file
> 
> This reduces the preprocessor expanded source size by 84,675 LoC:
> 
> gen         (   20 files):    71,349 to    1,523,934 (   21x)
> src         (  624 files):   367,410 to   53,253,894 (  145x)
> test        (  392 files):   490,503 to   37,436,176 (   76x)
> third_party (  432 files):   239,085 to    9,547,902 (   40x)
> total       ( 1520 files): 1,183,031 to  102,736,424 (   87x)
> 
> to
> 
> gen         (   20 files):    71,349 to    1,523,794 (   21x)
> src         (  624 files):   367,411 to   53,186,896 (  145x)
> test        (  392 files):   490,504 to   37,418,639 (   76x)
> third_party (  432 files):   239,085 to    9,547,902 (   40x)
> total       ( 1520 files): 1,183,033 to  102,651,749 (   87x)
> 
> 
> Change-Id: Ia8a79092051a42815b65e86a0784297915368c9b
> Reviewed-on: https://chromium-review.googlesource.com/c/1291471
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58266}

TBR=ulan@chromium.org,marja@chromium.org,sigurds@chromium.org,clemensh@chromium.org

Change-Id: I111f9bbef9e66cd1ee7f4206b6af1097f7c50e66
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/1379933Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58268}