Faster dotSource implementation for parsing autoload tab-complete

This[1] blog post describes a faster method of importing use script into
the powershell session by loading the file contents into memory proir to
letting powershell parse them for auto-complete values.

Reference:

1: https://becomelotr.wordpress.com/2017/02/13/expensive-dot-sourcing/

Testing:

Test cmderdev#1
---
dotsource(ms) | scriptblock(ms) | filename(test data)
------|------|----
  18  |  13  | Approve-Script.ps1
   6  |   2  | Clear-PrinterQueue.ps1
  14  |   3  | ConvertTo-ImageFormat.ps1
   9  |   2  | Copy-MultipleItems.ps1
   6  |   2  | Enter-RemoteSession.ps1
   6  |   3  | Get-CurrentUser.ps1
   7  |   3  | Get-LogonHistory.ps1
   6  |   2  | Get-SSID.ps1
   6  |   2  | Invoke-DscPullAndApply.ps1
   8  |   3  | Move-Drive.ps1
   7  |   2  | New-ComputerList.ps1
   6  |   2  | New-Directory.ps1
   6  |   3  | Set-Proxy.ps1
   7  |   2  | Shortcut.ps1
   6  |   3  | Start-Delprof.ps1
   6  |   3  | Suspend-Computer.ps1
   9  |   4  | SystemInformation.ps1
   6  |   3  | Test-ModuleSpeed.ps1
   7  |   5  | Test-TCPConnection.ps1
   6  |   2  | Update-ModuleReadMe.ps1
  11  |   3  | Watch-Here.ps1

Test cmderdev#2
---
dotsource(ms) | scriptblock(ms) | filename(test data)
------|------|-----
  40  |  24  |  Approve-Script.ps1
   8  |   4  |  Clear-PrinterQueue.ps1
  24  |  12  |  ConvertTo-ImageFormat.ps1
  14  |   8  |  Copy-MultipleItems.ps1
   7  |   4  |  Enter-RemoteSession.ps1
  10  |   4  |  Get-CurrentUser.ps1
  30  |   6  |  Get-LogonHistory.ps1
   6  |   4  |  Get-SSID.ps1
   7  |   4  |  Invoke-DscPullAndApply.ps1
  11  |   8  |  Move-Drive.ps1
  11  |   5  |  New-ComputerList.ps1
  11  |   4  |  New-Directory.ps1
   6  |   5  |  Set-Proxy.ps1
  11  |   5  |  Shortcut.ps1
  10  |  12  |  Start-Delprof.ps1
  12  |   5  |  Suspend-Computer.ps1
  69  |   5  |  SystemInformation.ps1
  11  |   4  |  Test-ModuleSpeed.ps1
   6  |   7  |  Test-TCPConnection.ps1
   8  |   4  |  Update-ModuleReadMe.ps1
  10  |   9  |  Watch-Here.ps1

vendor/profile.ps1

@@ -92,12 +92,15 @@ if (-not (test-path "$ENV:CMDER_ROOT\config\profile.d")) {
   mkdir "$ENV:CMDER_ROOT\config\profile.d"
 }
 
-pushd $ENV:CMDER_ROOT\config\profile.d
-foreach ($x in ls *.ps1) {
-  # write-host write-host Sourcing $x
-  . $x
+foreach ($file in (Get-ChildItem "$($env:CMDER_ROOT)\config\profile.d" -Filter '*.ps1') ) {
+    # Grab the contents of files at once and parse that as a script block.
+    # faster script loading, see: https://becomelotr.wordpress.com/2017/02/13/expensive-dot-sourcing/
+    . (
+        [scriptblock]::Create(
+            [io.file]::ReadAllText($file.fullname)
+        )
+    )
 }
-popd
 
 #
 # Prompt Section