[Issue 16513] Speed up TemplateInstance.findExistingInstance, hash by mangling

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=16513

--- Comment #3 from Martin Nowak <code at dawg.eu> ---
Managed to speed up the test case from 1.8s to 1.2s, almost completely
eliminating the lookup cost.
Still need to fix a few issues, the cppmangler thinks member variables are
static, we might not want to fill the idPool with unused identifiers (would
save some memory to just compute the hash), needs some more testing whether the
mangling is really bijective, if so we could only hash the string and ditch the
TemplateInstance.compare code.

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