Auto merge of #37392 - alexcrichton:more-disable-jemalloc, r=brson

Auto merge of #37392 - alexcrichton:more-disable-jemalloc, r=brson

Disable jemalloc on aarch64/powerpc

Sounds like jemalloc is broken on systems which differ in page size than the
host it was compiled on (unless an option was passed). This unfortunately
reduces the portability of binaries created and can often make Rust segfault by
default. For now let's patch over this by disabling jemalloc until we can figure
out a better solution.

Closes #36994
Closes #37320
cc jemalloc/jemalloc#467