[NFC] Remove redundant includes for llvm/ADT/SmallVector.h.

Author: varungandhi-apple

include/swift/AST/ExistentialLayout.h

@@ -20,7 +20,6 @@
 #include "swift/Basic/ArrayRefView.h"
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/Type.h"
-#include "llvm/ADT/SmallVector.h"
 
 namespace swift {
   class ProtocolDecl;

include/swift/Parse/Scope.h

@@ -21,7 +21,6 @@
 #include "swift/AST/Identifier.h"
 #include "swift/Basic/Debug.h"
 #include "swift/Basic/TreeScopedHashTable.h"
-#include "llvm/ADT/SmallVector.h"
 
 namespace swift {
   class ValueDecl;

include/swift/SIL/LinearLifetimeChecker.h

@@ -19,7 +19,6 @@
 #include "swift/SIL/SILInstruction.h"
 #include "swift/SIL/SILValue.h"
 #include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
 
 namespace swift {
 

include/swift/SILOptimizer/Analysis/Analysis.h

@@ -17,7 +17,6 @@
 #include "swift/SIL/Notifications.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
-#include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/Casting.h"
 
 namespace swift {