jemalloc: updated to 5.2.1

5.2.1

This release is primarily about Windows. A critical virtual memory leak is resolved on all Windows platforms. The regression was present in all releases since 5.0.0.

Bug fixes:

Fix a severe virtual memory leak on Windows. This regression was first released in 5.0.0.
Fix size 0 handling in posix_memalign(). This regression was first released in 5.2.0.
Fix the prof_log unit test which may observe unexpected backtraces from compiler optimizations. The test was first added in 5.2.0.
Fix the declaration of the extent_avail tree. This regression was first released in 5.1.0.
Fix an incorrect reference in jeprof. This functionality was first released in 3.0.0.
Fix an assertion on the deallocation fast-path. This regression was first released in 5.2.0.
Fix the TLS_MODEL attribute in headers. This regression was first released in 5.0.0.

Optimizations and refactors:

Implement opt.retain on Windows and enable by default on 64-bit.
Optimize away a branch on the operator delete path.
Add format annotation to the format generator function.
Refactor and improve the size class header generation.
Remove best fit.
Avoid blocking on background thread locks for stats.

(adam)