build: split apart SDK loops for standard and experimental

This splits apart the experimental SDK builds to a separate loop.
Furthermore, give the `Build-ExperimentalSDK` an explicit `-Static`
switch to record the fact that the experimental SDK is currently being
used for static build testing.

Author: compnerd

utils/build.ps1

@@ -2490,18 +2490,37 @@ function Build-Foundation {
     Get-ProjectBinaryCache $Platform DynamicFoundation
   }
 
+  $FoundationImage = if ($Static) {
+    "$(Get-SwiftSDK $Platform.OS -Identifier "$($Platform.OS)Experimental")\usr"
+  } else {
+    "$(Get-SwiftSDK $Platform.OS)\usr"
+  }
+
+  $SwiftFlags = if ($Static) {
+    @("-static-stdlib", "-Xfrontend", "-use-static-resource-dir")
+  } else {
+    @()
+  }
+
+  $SwiftSDK = if ($Static) {
+    Get-SwiftSDK $Platform.OS -Identifier "$($Platform.OS)Experimental"
+  } else {
+    Get-SwiftSDK $Platform.OS
+  }
+
   Build-CMakeProject `
     -Src $SourceCache\swift-corelibs-foundation `
     -Bin $FoundationBinaryCache `
-    -InstallTo $(if ($Static) { "$(Get-SwiftSDK $Platform.OS -Identifier "$($Platform.OS)Experimental")\usr" } else { "$(Get-SwiftSDK $Platform.OS)\usr" }) `
+    -InstallTo $FoundationImage `
     -Platform $Platform `
     -UseBuiltCompilers ASM,C,CXX,Swift `
-    -SwiftSDK (Get-SwiftSDK $Platform.OS) `
+    -SwiftSDK $SwiftSDK `
     -Defines @{
       BUILD_SHARED_LIBS = if ($Static) { "NO" } else { "YES" };
       CMAKE_FIND_PACKAGE_PREFER_CONFIG = "YES";
       CMAKE_NINJA_FORCE_RESPONSE_FILE = "YES";
       CMAKE_STATIC_LIBRARY_PREFIX_Swift = "lib";
+      CMAKE_Swift_FLAGS = $SwiftFlags;
       ENABLE_TESTING = "NO";
       FOUNDATION_BUILD_TOOLS = if ($Platform.OS -eq [OS]::Windows) { "YES" } else { "NO" };
       CURL_DIR = "$BinaryCache\$($Platform.Triple)\usr\lib\cmake\CURL";
@@ -3337,7 +3356,6 @@ if (-not $SkipBuild) {
 
   foreach ($Platform in $WindowsSDKPlatforms) {
     Invoke-BuildStep Build-SDK $Platform
-    Invoke-BuildStep Build-ExperimentalSDK $Platform
 
     Get-ChildItem "$(Get-SwiftSDK Windows)\usr\lib\swift\windows" -Filter "*.lib" -File -ErrorAction Ignore | ForEach-Object {
       Write-Host -BackgroundColor DarkRed -ForegroundColor White "$($_.FullName) is not nested in an architecture directory"
@@ -3347,29 +3365,48 @@ if (-not $SkipBuild) {
     Copy-Directory "$(Get-SwiftSDK Windows)\usr\bin" "$([IO.Path]::Combine((Get-InstallDir $Platform), "Runtimes", $ProductVersion, "usr"))"
   }
 
-  Write-PlatformInfoPlist Windows
   Install-SDK $WindowsSDKPlatforms
   Write-SDKSettings Windows
+
+  foreach ($Platform in $WindowsSDKPlatforms) {
+    Invoke-BuildStep Build-ExperimentalSDK $Platform
+    Get-ChildItem "$(Get-SwiftSDK Windows -Identifier WindowsExperimental)\usr\lib\swift_static\windows" -Filter "*.lib" -File -ErrorAction Ignore | ForEach-Object {
+      Write-Host -BackgroundColor DarkRed -ForegroundColor White "$($_.FullName) is not nested in an architecture directory"
+      Move-Item $_.FullName "$(Get-SwiftSDK Windows -Identifier WindowsExperimental)\usr\lib\swift_static\windows\$($Platform.Architecture.LLVMName)\" | Out-Null
+    }
+  }
+
   Install-SDK $WindowsSDKPlatforms -Identifier WindowsExperimental
   Write-SDKSettings Windows -Identifier WindowsExperimental
 
+  Write-PlatformInfoPlist Windows
+
   if ($Android) {
     foreach ($Platform in $AndroidSDKPlatforms) {
       Invoke-BuildStep Build-SDK $Platform
-      Invoke-BuildStep Build-ExperimentalSDK $Platform
 
       Get-ChildItem "$(Get-SwiftSDK Android)\usr\lib\swift\android" -File | Where-Object { $_.Name -match ".a$|.so$" } | ForEach-Object {
         Write-Host -BackgroundColor DarkRed -ForegroundColor White "$($_.FullName) is not nested in an architecture directory"
         Move-Item $_.FullName "$(Get-SwiftSDK Android)\usr\lib\swift\android\$($Platform.Architecture.LLVMName)\" | Out-Null
       }
     }
 
-    Write-PlatformInfoPlist Android
     Install-SDK $AndroidSDKPlatforms
     Write-SDKSettings Android
-    Install-SDK $AndroidSDKPlatforms -Identifiers AndroidExperimental
+
+    foreach ($Platform in $AndroidSDKPlatforms) {
+      Invoke-BuildStep Build-ExperimentalSDK $Platform
+      Get-ChildItem "$(Get-SwiftSDK Android -Identifier AndroidExperimental)\usr\lib\swift_static\android" -File | Where-Object { $_.Name -match ".a$" } | ForEach-Object {
+        Write-Host -BackgroundColor DarkRed -ForegroundColor White "$($_.FullName) is not nested in an architecture directory"
+        Move-Item $_.FullName "$(Get-SwiftSDK Android -Identifier AndroidExperimental)\usr\lib\swift_static\android\$($Platform.Architecture.LLVMName)\" | Out-Null
+      }
+    }
+
+    Install-SDK $AndroidSDKPlatforms -Identifier AndroidExperimental
     Write-SDKSettings Android -Identifier AndroidExperimental
 
+    Write-PlatformInfoPlist Android
+
     # Android swift-inspect only supports 64-bit platforms.
     $AndroidSDKPlatforms | Where-Object { @("arm64-v8a", "x86_64") -contains $_.Architecture.ABI } | ForEach-Object {
       Invoke-BuildStep Build-Inspect $_