[browser][coreCLR] linear memory, mmap, GC

[pavelsavara]

WASM linear memory is 32bit address space and doesn't support virtual mmap. That leads to memory fragmentation and performance issues.

Duplicate #117813

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[MihuBot]

I'm a bot. Here is a possible related and/or duplicate issue (I may be wrong):

• [wasm] High memory fragmentation on LOS allocations #118044

[pavelsavara]

Mono related fixes for the same problem

• [wasm] Fix fragmentation caused by large objects allocation #118099
• [wasm] stop using mmap/munmap #108512