tests/histedit-helpers.sh

profiling: add statprof support for Chrome trace viewer rendering

We synthesize function call begin/end events from snapshots, and
try (configurably) to eliminate "noisy" stack frames.

Example invocation:

hg --config profiling.output=$HOME/Desktop/clone.json \
   --config profiling.statformat=chrome \
   --profile clone https://www.mercurial-scm.org/repo/hg

fixbundle() {
    grep -v 'saving bundle' | grep -v 'saved backup' | \
        grep -v added | grep -v adding | \
        grep -v "unable to find 'e' for patching" | \
        grep -v "e: No such file or directory" | \
    cat
}