Improve warning when additional PowerShell isn't found

Since we added logic which searches for possible intended permutations
of the given additional PowerShell path, we needed to make the warning
show only if none of the permutations were found. This was accomplished
by suppressing it in the first iterator and then yielding it again after
the permutations were exhausted with the warning unsuppressed.

Author: andyleejordan

src/platform.ts

@@ -239,17 +239,17 @@ export class PowerShellExeFinder {
                 }
 
                 exePath = untildify(exePath);
-
-                // Always search for what the user gave us first
-                yield new PossiblePowerShellExe(exePath, versionName);
-
-                // Also search for `pwsh[.exe]` and `powershell[.exe]` if missing
                 const args: [string, undefined, boolean, boolean]
                     // Must be a tuple type and is suppressing the warning
                     = [versionName, undefined, true, true];
 
-                // Handle Windows where '.exe' and 'powershell' are things
+                // Always search for what the user gave us first, but with the warning
+                // suppressed so we can display it after all possibilities are exhausted
+                yield new PossiblePowerShellExe(exePath, ...args);
+
+                // Also search for `pwsh[.exe]` and `powershell[.exe]` if missing
                 if (this.platformDetails.operatingSystem === OperatingSystem.Windows) {
+                    // Handle Windows where '.exe' and 'powershell' are things
                     if (!exePath.endsWith("pwsh.exe") && !exePath.endsWith("powershell.exe")) {
                         if (exePath.endsWith("pwsh") || exePath.endsWith("powershell")) {
                             // Add extension if that was missing
@@ -260,9 +260,13 @@ export class PowerShellExeFinder {
                         yield new PossiblePowerShellExe(path.join(exePath, "pwsh.exe"), ...args);
                         yield new PossiblePowerShellExe(path.join(exePath, "powershell.exe"), ...args);
                     }
-                } else if (!exePath.endsWith("pwsh")) { // Always just 'pwsh' on non-Windows
+                } else if (!exePath.endsWith("pwsh")) {
+                    // Always just 'pwsh' on non-Windows
                     yield new PossiblePowerShellExe(path.join(exePath, "pwsh"), ...args);
                 }
+
+                // If we're still being iterated over, no permutation of the given path existed so yield an object with the warning unsuppressed
+                yield new PossiblePowerShellExe(exePath, versionName, false, undefined, false);
             }
         }
     }