[parser] Redo loops in _parsePrecedenceExpressionLoop

pkg/analyzer/lib/src/dart/ast/ast.dart:

JIT (tokens per microsecond):
6.3638% +/- 1.0454% (1.58 +/- 0.26) (24.83 -> 26.41)

AOT (tokens per microsecond):
7.2915% +/- 0.9305% (2.36 +/- 0.30) (32.32 -> 34.68)

Benchmarker (AOT):
```
msec task-clock:u: -6.8409% +/- 0.8755% (-171.31 +/- 21.92) (2504.18 -> 2332.87)
cycles:u: -6.9075% +/- 0.8852% (-749508513.10 +/- 96049038.00) (10850656620.68 -> 10101148107.58)
instructions:u: -8.4679% +/- 0.0000% (-1836882019.72 +/- 365.67) (21692257748.84 -> 19855375729.12)
branch-misses:u: -8.1101% +/- 2.9770% (-2397153.78 +/- 879942.27) (29557566.12 -> 27160412.34)
seconds time elapsed: -6.8416% +/- 0.8753% (-0.17 +/- 0.02) (2.51 -> 2.33)
seconds user: -6.8903% +/- 0.8879% (-0.17 +/- 0.02) (2.48 -> 2.31)
```


pkg/front_end/lib/src/type_inference/inference_visitor.dart:

JIT (tokens per microsecond):
9.6105% +/- 0.7962% (1.93 +/- 0.16) (20.03 -> 21.96)

AOT (tokens per microsecond):
11.6797% +/- 1.0269% (3.09 +/- 0.27) (26.47 -> 29.57)

Benchmarker (AOT):
```
msec task-clock:u: -9.6901% +/- 0.8600% (-222.58 +/- 19.75) (2297.04 -> 2074.46)

cycles:u: -9.7982% +/- 0.8724% (-974597873.18 +/- 86776670.77) (9946712953.30 -> 8972115080.12)
instructions:u: -15.1329% +/- 0.0000% (-3186976224.52 +/- 513.54) (21059918941.74 -> 17872942717.22)
seconds time elapsed: -9.6858% +/- 0.8600% (-0.22 +/- 0.02) (2.30 -> 2.08)
seconds user: -9.7480% +/- 0.8797% (-0.22 +/- 0.02) (2.28 -> 2.05)
```
Change-Id: Ie143d11acd36e6a7ebff79862481d7c888300844
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/443520
Commit-Queue: Jens Johansen <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>

Author: jensjoha