SwiftDriver: repair the generation of CodeView debug info

Correct the spelling for the argument for the `-debug-info-format`. We were incorrectly emitting the enum name instead of the value, which would break the build when CodeView was enabled.

Author: compnerd

Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift

@@ -196,7 +196,7 @@ extension Driver {
  try commandLine.appendLast(.enablePrivateImports, from: &parsedOptions)
  try commandLine.appendLast(in: .g, from: &parsedOptions)
  if debugInfo.level != nil {
- commandLine.appendFlag("-debug-info-format=\(debugInfo.format)")
+ commandLine.appendFlag("-debug-info-format=\(debugInfo.format.rawValue)")
  if isFrontendArgSupported(.dwarfVersion) {
  commandLine.appendFlag("-dwarf-version=\(debugInfo.dwarfVersion)")
  }

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -560,6 +560,16 @@ final class SwiftDriverTests: XCTestCase {
  try assertNoDriverDiagnostics(args: "swiftc", "foo.swift", "-emit-module", "-g", "-debug-info-format=codeview") { driver in
  XCTAssertEqual(driver.debugInfo.level, .astTypes)
  XCTAssertEqual(driver.debugInfo.format, .codeView)
+
+ let jobs = try driver.planBuild()
+ XCTAssertTrue(jobs[0].commandLine.contains(.flag("-debug-info-format=codeview")))
+ }
+
+ try assertNoDriverDiagnostics(args: "swiftc", "foo.swift", "-emit-module", "-g", "-debug-info-format=dwarf") { driver in
+ XCTAssertEqual(driver.debugInfo.format, .dwarf)
+
+ let jobs = try driver.planBuild()
+ XCTAssertTrue(jobs[0].commandLine.contains(.flag("-debug-info-format=dwarf")))
  }
 
  try assertDriverDiagnostics(args: "swiftc", "foo.swift", "-emit-module", "-debug-info-format=dwarf") {