The following methods didn't need the use of context, and could
be replaced by NoContextConstant():
 * AllocateSeqOneByteString
 * AllocateSeqTwoByteString
 * StringBuiltinsAssembler::GenerateStringEqual
 * StringBuiltinsAssembler::StringEqual_Core
 * StringBuiltinsAssembler::GenerateStringRelationalComparison

Change-Id: I98068980377450daef7c999e3d413e839f66fda9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1758321Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63246}