[NFC] Clean up unused simulator special cases

The previous commit makes various simulator-specific platform helpers dead code. Remove them.

Author: beccadax

include/swift/Basic/Platform.h

@@ -71,11 +71,6 @@ namespace swift {
   /// Returns the platform Kind for Darwin triples.
   DarwinPlatformKind getDarwinPlatformKind(const llvm::Triple &triple);
 
-  /// Maps an arbitrary platform to its non-simulator equivalent.
-  ///
-  /// If \p platform is not a simulator platform, it will be returned as is.
-  DarwinPlatformKind getNonSimulatorPlatform(DarwinPlatformKind platform);
-
   /// Returns the architecture component of the path for a given target triple.
   ///
   /// Typically this is used for mapping the architecture component of the

lib/Basic/Platform.cpp

@@ -123,23 +123,6 @@ DarwinPlatformKind swift::getDarwinPlatformKind(const llvm::Triple &triple) {
   llvm_unreachable("Unsupported Darwin platform");
 }
 
-DarwinPlatformKind swift::getNonSimulatorPlatform(DarwinPlatformKind platform) {
-  switch (platform) {
-  case DarwinPlatformKind::MacOS:
-    return DarwinPlatformKind::MacOS;
-  case DarwinPlatformKind::IPhoneOS:
-  case DarwinPlatformKind::IPhoneOSSimulator:
-    return DarwinPlatformKind::IPhoneOS;
-  case DarwinPlatformKind::TvOS:
-  case DarwinPlatformKind::TvOSSimulator:
-    return DarwinPlatformKind::TvOS;
-  case DarwinPlatformKind::WatchOS:
-  case DarwinPlatformKind::WatchOSSimulator:
-    return DarwinPlatformKind::WatchOS;
-  }
-  llvm_unreachable("Unsupported Darwin platform");
-}
-
 static StringRef getPlatformNameForDarwin(const DarwinPlatformKind platform) {
   switch (platform) {
   case DarwinPlatformKind::MacOS:

lib/Driver/DarwinToolChains.cpp

@@ -89,12 +89,9 @@ toolchains::Darwin::constructInvocation(const InterpretJobAction &job,
 }
 
 static StringRef
-getDarwinLibraryNameSuffixForTriple(const llvm::Triple &triple,
-                                    bool distinguishSimulator = true) {
+getDarwinLibraryNameSuffixForTriple(const llvm::Triple &triple) {
   const DarwinPlatformKind kind = getDarwinPlatformKind(triple);
-  const DarwinPlatformKind effectiveKind =
-      distinguishSimulator ? kind : getNonSimulatorPlatform(kind);
-  switch (effectiveKind) {
+  switch (kind) {
   case DarwinPlatformKind::MacOS:
     return "osx";
   case DarwinPlatformKind::IPhoneOS: