[AST] Split FileUnit and its subclasses out of Module.h

Most of AST, Parse, and Sema deal with FileUnits regularly, but SIL
and IRGen certainly don't. Split FileUnit out into its own header to
cut down on recompilation times when something changes.

No functionality change.

Author: jrose-apple

include/swift/AST/FileUnit.h

@@ -16,7 +16,7 @@
 #ifndef SWIFT_CLANGIMPORTER_CLANGMODULE_H
 #define SWIFT_CLANGIMPORTER_CLANGMODULE_H
 
-#include "swift/AST/Module.h"
+#include "swift/AST/FileUnit.h"
 #include "swift/ClangImporter/ClangImporter.h"
 #include "clang/AST/ExternalASTSource.h"
 

include/swift/AST/Module.h

@@ -20,6 +20,7 @@
 
 #include "swift/AST/DiagnosticConsumer.h"
 #include "swift/AST/DiagnosticEngine.h"
+#include "swift/AST/FileUnit.h"
 #include "swift/AST/IRGenOptions.h"
 #include "swift/AST/LinkLibrary.h"
 #include "swift/AST/Module.h"

include/swift/ClangImporter/ClangModule.h

@@ -18,6 +18,7 @@
 
 #include "swift/AST/ASTTypeIDs.h"
 #include "swift/AST/Evaluator.h"
+#include "swift/AST/FileUnit.h"
 #include "swift/AST/SimpleRequest.h"
 #include "swift/IDE/Utils.h"
 #include "swift/IDE/IDETypeIDs.h"

include/swift/Frontend/Frontend.h

@@ -13,6 +13,7 @@
 #ifndef SWIFT_SERIALIZATION_MODULELOADER_H
 #define SWIFT_SERIALIZATION_MODULELOADER_H
 
+#include "swift/AST/FileUnit.h"
 #include "swift/AST/Module.h"
 #include "swift/AST/ModuleLoader.h"
 #include "llvm/Support/MemoryBuffer.h"

include/swift/IDE/IDERequests.h

@@ -22,6 +22,7 @@
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/AST/DiagnosticsSema.h"
 #include "swift/AST/ExistentialLayout.h"
+#include "swift/AST/FileUnit.h"
 #include "swift/AST/ForeignErrorConvention.h"
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/GenericSignature.h"

include/swift/Serialization/SerializedModuleLoader.h

@@ -17,6 +17,7 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/ASTPrinter.h"
 #include "swift/AST/ASTVisitor.h"
+#include "swift/AST/FileUnit.h"
 #include "swift/AST/ForeignErrorConvention.h"
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/Initializer.h"

lib/AST/ASTContext.cpp

@@ -18,6 +18,7 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/ASTVisitor.h"
 #include "swift/AST/ExistentialLayout.h"
+#include "swift/AST/FileUnit.h"
 #include "swift/AST/GenericSignature.h"
 #include "swift/AST/Initializer.h"
 #include "swift/AST/LazyResolver.h"

lib/AST/ASTDumper.cpp

@@ -22,6 +22,7 @@
 #include "swift/AST/Comment.h"
 #include "swift/AST/Decl.h"
 #include "swift/AST/Expr.h"
+#include "swift/AST/FileUnit.h"
 #include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/Module.h"
 #include "swift/AST/NameLookup.h"