Remove unused header

Author: zyn0217

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -12,7 +12,6 @@
 #include "TreeTransform.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
-#include "clang/AST/ASTLambda.h"
 #include "clang/AST/ASTMutationListener.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/DependentDiagnostic.h"