Index --watch CPU usage

The watcher which gets started by the VSCode or IntelliJ plugin (latest versions) constantly uses CPU even though nothing is happening, and sometimes burning lots of CPU time.

node --prof %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\@appland\appmap\built\cli.js index --watch --appmap-dir .
AppMaps processed: 0

node --prof-process isolate*.log output:

[Bottom up (heavy) profile]:
   ticks parent  name
  26086   91.6%  C:\WINDOWS\SYSTEM32\ntdll.dll
    277    1.1%    LazyCompile: *lstat node:fs:1490:15
    227   81.9%      LazyCompile: *Glob._processReaddir %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:368:43
    227  100.0%        LazyCompile: *Glob._process %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:295:36
    208   91.6%          LazyCompile: *<anonymous> %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:625:43
    208  100.0%            LazyCompile: *RES %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\inflight\inflight.js:18:28
     19    8.4%          LazyCompile: *Glob._processGlobStar2 %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:631:45
     19  100.0%            Function: ^<anonymous> %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:625:43
     19    6.9%      LazyCompile: *<anonymous> %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\readdirp\index.js:127:52
     19  100.0%        LazyCompile: *_read %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\readdirp\index.js:118:14
     19  100.0%          C:\Code\node-v18.13.0-win-x64\node.exe
     12    4.3%      LazyCompile: *Glob._readdir %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:525:36
     12  100.0%        LazyCompile: *Glob._process %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:295:36
     11   91.7%          LazyCompile: *<anonymous> %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:625:43
     11  100.0%            LazyCompile: *RES %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\inflight\inflight.js:18:28
      1    8.3%          LazyCompile: *Glob._processGlobStar2 %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:631:45
      1  100.0%            Function: ^<anonymous> %APPDATA%\Code\User\globalStorage\appland.appmap\node_modules\glob\glob.js:625:43

To me this looks like it's busy scanning the directories.
Also see https://github.com/getappmap/appmap-js/issues/969#issuecomment-1424739918.

Start with the index --watch --appmap-dir . CLI entry point and reproduce the idle CPU usage using the profiling command shown. Inspect the watcher’s glob and readdirp activity identified in the profile; done means the watcher remains idle without continuously scanning directories or consuming substantial CPU.