[dev.typeparams] internal/buildcfg: turn on register ABI by default on ARM64

This CL enables all regabi experiments on ARM64 by default.
regabiwrappers and regabireflect are enabled in the previous CLs.
regabidefer is already enabled everywhere. regabig is no-op on
ARM64 as it already has a G register. regabiargs is enabled in
this CL.

Go1 benchmarks results (GOEXPERIMENT=regabi vs. none, on macOS/ARM64):

name                     old time/op    new time/op     delta
BinaryTree17-8              1.20s ± 1%      1.02s ± 0%  -15.08%  (p=0.000 n=9+9)
Fannkuch11-8                1.55s ± 0%      1.57s ± 0%   +1.53%  (p=0.000 n=9+8)
FmtFprintfEmpty-8          22.5ns ± 3%     14.7ns ± 1%  -34.47%  (p=0.000 n=10+8)
FmtFprintfString-8         38.4ns ± 0%     28.8ns ± 0%  -24.99%  (p=0.000 n=9+9)
FmtFprintfInt-8            38.7ns ± 2%     34.5ns ± 0%  -10.79%  (p=0.000 n=10+7)
FmtFprintfIntInt-8         61.1ns ± 1%     57.9ns ± 0%   -5.23%  (p=0.000 n=10+8)
FmtFprintfPrefixedInt-8    69.9ns ± 0%     64.4ns ± 0%   -7.78%  (p=0.000 n=8+8)
FmtFprintfFloat-8           106ns ± 0%       76ns ± 0%  -28.12%  (p=0.000 n=7+10)
FmtManyArgs-8               273ns ± 0%      236ns ± 1%  -13.57%  (p=0.000 n=9+10)
GobDecode-8                3.09ms ± 1%     2.02ms ± 0%  -34.70%  (p=0.000 n=9+10)
GobEncode-8                2.45ms ± 1%     1.44ms ± 1%  -41.26%  (p=0.000 n=10+10)
Gzip-8                      128ms ± 0%      124ms ± 0%   -2.89%  (p=0.000 n=7+8)
Gunzip-8                   23.6ms ± 1%     19.8ms ± 0%  -16.15%  (p=0.000 n=10+9)
HTTPClientServer-8         27.4µs ± 1%     26.3µs ± 0%   -4.05%  (p=0.000 n=10+10)
JSONEncode-8               4.47ms ± 1%     3.45ms ± 1%  -22.73%  (p=0.000 n=10+9)
JSONDecode-8               21.5ms ± 0%     17.2ms ± 0%  -19.78%  (p=0.000 n=9+9)
Mandelbrot200-8            2.33ms ± 1%     2.33ms ± 1%     ~     (p=0.842 n=9+10)
GoParse-8                  1.62ms ± 1%     1.32ms ± 1%  -18.67%  (p=0.000 n=10+10)
RegexpMatchEasy0_32-8      33.1ns ± 0%     26.3ns ± 0%  -20.50%  (p=0.000 n=8+10)
RegexpMatchEasy0_1K-8       121ns ± 6%      121ns ± 8%     ~     (p=0.926 n=10+10)
RegexpMatchEasy1_32-8      31.4ns ± 0%     24.7ns ± 0%  -21.50%  (p=0.000 n=9+10)
RegexpMatchEasy1_1K-8       177ns ± 0%      140ns ± 0%  -20.70%  (p=0.000 n=10+9)
RegexpMatchMedium_32-8     3.02ns ± 3%     2.12ns ± 0%  -29.73%  (p=0.000 n=10+10)
RegexpMatchMedium_1K-8     19.8µs ± 2%     17.1µs ± 0%  -13.50%  (p=0.000 n=9+9)
RegexpMatchHard_32-8        940ns ± 0%      872ns ± 0%   -7.20%  (p=0.000 n=9+8)
RegexpMatchHard_1K-8       28.5µs ± 1%     26.5µs ± 0%   -7.06%  (p=0.000 n=10+10)
Revcomp-8                   186ms ± 1%      179ms ± 1%   -3.66%  (p=0.000 n=10+10)
Template-8                 30.3ms ± 0%     22.3ms ± 0%  -26.58%  (p=0.000 n=8+9)
TimeParse-8                 133ns ± 0%      117ns ± 0%  -12.40%  (p=0.000 n=10+10)
TimeFormat-8                176ns ± 0%      141ns ± 0%  -19.92%  (p=0.000 n=8+9)
[Geo mean]                 21.4µs          17.8µs       -16.81%

name                     old speed      new speed       delta
GobDecode-8               249MB/s ± 1%    381MB/s ± 0%  +53.13%  (p=0.000 n=9+10)
GobEncode-8               314MB/s ± 1%    534MB/s ± 1%  +70.25%  (p=0.000 n=10+10)
Gzip-8                    152MB/s ± 0%    156MB/s ± 0%   +2.97%  (p=0.000 n=7+8)
Gunzip-8                  822MB/s ± 1%    981MB/s ± 0%  +19.26%  (p=0.000 n=10+9)
JSONEncode-8              434MB/s ± 1%    562MB/s ± 1%  +29.41%  (p=0.000 n=10+9)
JSONDecode-8             90.3MB/s ± 0%  112.5MB/s ± 0%  +24.66%  (p=0.000 n=9+9)
GoParse-8                35.7MB/s ± 1%   43.9MB/s ± 1%  +22.96%  (p=0.000 n=10+10)
RegexpMatchEasy0_32-8     967MB/s ± 0%   1216MB/s ± 0%  +25.78%  (p=0.000 n=8+10)
RegexpMatchEasy0_1K-8    8.46GB/s ± 6%   8.45GB/s ± 7%     ~     (p=0.912 n=10+10)
RegexpMatchEasy1_32-8    1.02GB/s ± 0%   1.30GB/s ± 0%  +27.40%  (p=0.000 n=9+10)
RegexpMatchEasy1_1K-8    5.78GB/s ± 0%   7.29GB/s ± 0%  +26.10%  (p=0.000 n=10+9)
RegexpMatchMedium_32-8    331MB/s ± 2%    471MB/s ± 0%  +42.29%  (p=0.000 n=10+10)
RegexpMatchMedium_1K-8   51.7MB/s ± 2%   59.8MB/s ± 0%  +15.60%  (p=0.000 n=9+9)
RegexpMatchHard_32-8     34.0MB/s ± 0%   36.7MB/s ± 0%   +7.75%  (p=0.000 n=9+8)
RegexpMatchHard_1K-8     35.9MB/s ± 1%   38.6MB/s ± 0%   +7.59%  (p=0.000 n=10+10)
Revcomp-8                1.37GB/s ± 1%   1.42GB/s ± 1%   +3.79%  (p=0.000 n=10+10)
Template-8               64.0MB/s ± 0%   87.1MB/s ± 0%  +36.20%  (p=0.000 n=8+9)
[Geo mean]                299MB/s         368MB/s       +23.16%

Binary sizes:
                old            new
hello           1180994        1162626      -1.6%
cmd/compile     23455858       22833970     -2.7%
cmd/link        6425010        6332978      -1.4%

Text sizes:
                old            new
hello           458752         425984       -7.1%
cmd/compile     10190848       9355264      -8.2%
cmd/link        2621440        2441216      -6.9%

Change-Id: I52c10c11bb8fe5952b7043f9dbf09573ef71d2b0
Reviewed-on: https://go-review.googlesource.com/c/go/+/324890


Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>