Rename the SwiftPM entry point.

This PR renames the SwiftPM entry point function such that it does not need to be SPI. By marking it SPI, we unintentionally made it very difficult to use with a toolchain that does not include private module information.

The PR continues to export the old symbol name as used by SwiftPM; once we've updated SwiftPM to match, we will remove the old function.

Author: grynspan

Sources/Testing/Running/EntryPoint.swift

@@ -20,9 +20,7 @@ private import TestingInternals
 ///
 /// - Warning: This function is used by Swift Package Manager. Do not call it
 ///   directly.
-@_spi(SwiftPackageManagerSupport)
-@_disfavoredOverload
-public func swiftPMEntryPoint() async -> CInt {
+@_disfavoredOverload public func __swiftPMEntryPoint() async -> CInt {
   @Locked var exitCode = EXIT_SUCCESS
 
   do {
@@ -68,10 +66,21 @@ public func swiftPMEntryPoint() async -> CInt {
 ///
 /// - Warning: This function is used by Swift Package Manager. Do not call it
 ///   directly.
+public func __swiftPMEntryPoint() async -> Never {
+  let exitCode: CInt = await __swiftPMEntryPoint()
+  exit(exitCode)
+}
+
+/// Call `__swiftPMEntryPoint()`.
+///
+/// This function is an old alias of `__swiftPMEntryPoint()`. It will be removed
+/// in the near future.
+///
+/// - Warning: This function is used by Swift Package Manager. Do not call it
+///   directly.
 @_spi(SwiftPackageManagerSupport)
 public func swiftPMEntryPoint() async -> Never {
-  let exitCode: CInt = await swiftPMEntryPoint()
-  exit(exitCode)
+  await __swiftPMEntryPoint()
 }
 
 // MARK: -