runtime: reuse freed memory blocks on wasm
When compiling Go programs to WebAssembly, the memory allocation
strategy was neither releasing memory to the OS nor reusing blocks freed
by calls to runtime.sysFreeOS.
This CL unifies the plan9 and wasm memory management strategy
since both platforms use a linear memory space and do not have a
mechanism for returning memory blocks to the OS.
Fixes #59061
Change-Id: I282ba93c0fe1a0961a31c0825b2a7e0478b8713d
GitHub-Last-Rev:
1c485be4fb798679fde7db148392de558a6fa97c
GitHub-Pull-Request: golang/go#59065
Reviewed-on: https://go-review.googlesource.com/c/go/+/476717
Reviewed-by: Julien Fabre <ju.pryz@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>
Reviewed-by: Evan Phoenix <evan@phx.io>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>
Run-TryBot: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>