Prevent upload script uploading from the wrong directory (GH-7953)

Tools/msi/uploadrelease.ps1

@@ -39,6 +39,10 @@ param(
 if (-not $build) { throw "-build option is required" }
 if (-not $user) { throw "-user option is required" }
 
+if (-not ((Test-Path "$build\win32\python-*.exe") -or (Test-Path "$build\amd64\python-*.exe"))) {
+    throw "-build argument does not look like a 'build' directory"
+}
+
 function find-putty-tool {
     param ([string]$n)
     $t = gcm $n -EA 0
@@ -57,7 +61,6 @@ $p = gci -r "$build\python-*.exe" | `
 "Uploading version $($p[0]) $($p[1])"
 "  from: $build"
 "    to: $($server):$target/$($p[0])"
-" using: $plink and $pscp"
 ""
 
 if (-not $skipupload) {
@@ -65,6 +68,9 @@ if (-not $skipupload) {
     $pscp = find-putty-tool "pscp"
     $plink = find-putty-tool "plink"
 
+    "Upload using $pscp and $plink"
+    ""
+
     pushd $build
     $doc = gci python*.chm, python*.chm.asc
     popd