Add support for jemalloc

[mathomp4]

Tests by @atrayano found that at high resolution using jemalloc really seemed to help with the memory usage. Indeed, it seems to be true at all resolutions.

For example, at C24 it seems to go from 23% to 18%. At C720, I ran three runs each with and without using jemalloc and:

The higher lines are the 'stock' runs and the lower are 'jemalloc'.

Adding this support to GEOS is not hard at all and I'll use this as a meta-issue to track PRs.

But I suppose the question (as both @tclune and @atrayano have thought as well): Is this "real"? Or are we perhaps not tracking the right thing?

And then does it work at NAS?

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Repos

• ESMA_env Updates to enable jemalloc build ESMA_env#116
• ESMA_cmake Add FindJeMalloc.cmake ESMA_cmake#349
• GEOSgcm_App Updates to enable jemalloc build GEOSgcm_App#568

Run Tests

• NCCS SLES12
• NCCS SLES15
• NAS
• macOS Laptop

Trickle Tests

• Does it work as expected without a jemalloc installed (i.e., only cmake and app changes)?