[Swift] Update for header reorganization (#1997)

No functionality change.

Author: jrose-apple

include/lldb/Symbol/SwiftASTContext.h

@@ -41,6 +41,7 @@ class SearchPathOptions;
 class SILModule;
 class VarDecl;
 class ModuleDecl;
+class SourceFile;
 struct PrintOptions;
 class MemoryBufferSerializedModuleLoader;
 namespace irgen {

source/Plugins/ExpressionParser/Swift/SwiftASTManipulator.cpp

@@ -29,6 +29,7 @@
 #include "swift/AST/NameLookup.h"
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/Pattern.h"
+#include "swift/AST/SourceFile.h"
 #include "swift/AST/Stmt.h"
 #include "swift/AST/TypeRepr.h"
 #include "swift/AST/Types.h"

source/Plugins/ExpressionParser/Swift/SwiftASTManipulator.h

@@ -29,6 +29,7 @@ class ExtensionDecl;
 class FuncDecl;
 class RepeatWhileStmt;
 class ReturnStmt;
+class SourceFile;
 class VarDecl;
 } // namespace swift