6fab57edad
Get memory info on Linux from the proc filesystem
(`/proc/<pid>/status`).
E.g.
```
Initial analysis: 2.600716
Completion after change: 0.783488
peak virtual memory size: 2288 MB
total program size (virtual): 2235 MB
peak resident set size ("high water mark"): 302 MB
size of memory portions (rss): 257 MB
```
Change-Id: I3c16d00569d6427627a8629c465e85a15f962c32
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/417162
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>