[Frontend] Move the argument converter header files into lib/ (#15417)

...since they don't need to be accessed from other libraries. No
intended functionality change.

Author: jrose-apple

lib/Frontend/ArgsToFrontendInputsConverter.cpp

@@ -10,11 +10,11 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "swift/Frontend/ArgsToFrontendInputsConverter.h"
+#include "ArgsToFrontendInputsConverter.h"
 
+#include "ArgsToFrontendOutputsConverter.h"
 #include "swift/AST/DiagnosticsFrontend.h"
 #include "swift/Basic/Defer.h"
-#include "swift/Frontend/ArgsToFrontendOutputsConverter.h"
 #include "swift/Frontend/FrontendOptions.h"
 #include "swift/Option/Options.h"
 #include "swift/Parse/Lexer.h"

include/swift/Frontend/ArgsToFrontendInputsConverter.h lib/Frontend/ArgsToFrontendInputsConverter.h

@@ -10,12 +10,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "swift/Frontend/ArgsToFrontendOptionsConverter.h"
+#include "ArgsToFrontendOptionsConverter.h"
 
+#include "ArgsToFrontendInputsConverter.h"
+#include "ArgsToFrontendOutputsConverter.h"
 #include "swift/AST/DiagnosticsFrontend.h"
 #include "swift/Basic/Platform.h"
-#include "swift/Frontend/ArgsToFrontendInputsConverter.h"
-#include "swift/Frontend/ArgsToFrontendOutputsConverter.h"
 #include "swift/Frontend/Frontend.h"
 #include "swift/Option/Options.h"
 #include "swift/Option/SanitizerOptions.h"

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -9,12 +9,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "swift/Frontend/ArgsToFrontendOutputsConverter.h"
+#include "ArgsToFrontendOutputsConverter.h"
 
+#include "ArgsToFrontendInputsConverter.h"
+#include "ArgsToFrontendOptionsConverter.h"
 #include "swift/AST/DiagnosticsFrontend.h"
 #include "swift/Basic/Platform.h"
-#include "swift/Frontend/ArgsToFrontendInputsConverter.h"
-#include "swift/Frontend/ArgsToFrontendOptionsConverter.h"
 #include "swift/Frontend/Frontend.h"
 #include "swift/Frontend/OutputFileMap.h"
 #include "swift/Option/Options.h"

include/swift/Frontend/ArgsToFrontendOptionsConverter.h lib/Frontend/ArgsToFrontendOptionsConverter.h

@@ -12,9 +12,9 @@
 
 #include "swift/Frontend/Frontend.h"
 
+#include "ArgsToFrontendOptionsConverter.h"
 #include "swift/AST/DiagnosticsFrontend.h"
 #include "swift/Basic/Platform.h"
-#include "swift/Frontend/ArgsToFrontendOptionsConverter.h"
 #include "swift/Option/Options.h"
 #include "swift/Option/SanitizerOptions.h"
 #include "swift/Strings.h"