Reduce allocations in the C# lexer ctor #76544
Open
+69
−14
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The lexer ctor shows as about 0.6% of all allocations over the lifetime of the RoslynCodeAnalysisProcess in the csharp editing speedometer tests.
There was already the concept of the LexerCache which had some pooling usage in it. This PR moves a couple other members to it to allow for their pooling.
Speedometer results look quite promising:
Allocations under Lexer.ctor in IncPaths reduced from 60 MB to 1.5 MB
Allocations under Lexer in IncPaths reduced from 1.57 GB to 1.36 GB