RFR: 8314029: Add file name parameter to Compiler.perfmap [v8]

[Yi-Fan Tsai]

> `jcmd Compiler.perfmap` uses the hard-coded file name for a perf map: `/tmp/perf-%d.map`. This change adds an optional argument for specifying a file name.
> 
> `jcmd PID help Compiler.perfmap` shows the following usage.
> 
> 
> Compiler.perfmap
> Write map file for Linux perf tool.
> 
> Impact: Low
> 
> Syntax : Compiler.perfmap  [<filename>]
> 
> Arguments:
>         filename : [optional] Name of the map file (STRING, no default value)
> 
> 
> The following section of man page is also updated. (`man -l src/jdk.jcmd/share/man/jcmd.1`)
> 
> 
>        Compiler.perfmap [arguments] (Linux only)
>               Write map file for Linux perf tool.
> 
>               Impact: Low
> 
>               arguments:
> 
>               · filename: (Optional) Name of the map file (STRING, no default value)
> 
>               If filename is not specified, a default file name is chosen using the pid of the target JVM process.  For example, if the pid is 12345,  then
>               the default filename will be /tmp/perf-12345.map.

Yi-Fan Tsai has updated the pull request incrementally with one additional commit since the last revision:

  Update copyright of PerfMapTest

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/15871/files
  - new: https://git.openjdk.org/jdk/pull/15871/files/dbe223c5..e1b0b162

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15871&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15871&range=06-07

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/15871.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15871/head:pull/15871

PR: https://git.openjdk.org/jdk/pull/15871