Merge pull request swiftlang#1845 from swiftlang/mracek/embedded-ios-os-version

[embedded] Skip checking OS versions of target triples when Embedded Swift is used

Author: kubamracek

Sources/SwiftDriver/Toolchains/DarwinToolchain.swift

@@ -238,6 +238,11 @@ public final class DarwinToolchain: Toolchain {
       return
     }
 
+    // Embedded Swift should accept all target triples / OS versions / arch combinations
+    guard !parsedOptions.isEmbeddedEnabled else {
+      return
+    }
+
     // Check minimum supported OS versions. Note that Mac Catalyst falls into the iOS device case. The driver automatically uplevels the deployment target to iOS >= 13.1.
     let minVersions: [Triple.OS: (DarwinPlatform, Triple.Version)] = [
       .macosx: (.macOS, Triple.Version(10, 9, 0)),

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -6880,6 +6880,13 @@ final class SwiftDriverTests: XCTestCase {
       }
     }
 
+    // 32-bit iOS jobs under Embedded should be allowed regardless of OS version
+    do {
+      try Driver(args: ["swiftc", "-c", "-target", "armv7-apple-ios8", "-enable-experimental-feature", "Embedded", "foo.swift"])
+      try Driver(args: ["swiftc", "-c", "-target", "armv7-apple-ios12.1", "-enable-experimental-feature", "Embedded", "foo.swift"])
+      try Driver(args: ["swiftc", "-c", "-target", "armv7-apple-ios16", "-enable-experimental-feature", "Embedded", "foo.swift"])
+    }
+
     do {
       let diags = DiagnosticsEngine()
       var driver = try Driver(args: ["swiftc", "-target", "arm64-apple-macosx10.13",  "test.swift", "-enable-experimental-feature", "Embedded", "-parse-as-library", "-wmo", "-o", "a.out", "-module-name", "main", "-enable-library-evolution"], diagnosticsEngine: diags)