Add arguments() to CXXConstructExpr so the same interface as with CallExpr can be used.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220558 91177308-0d34-0410-b5e6-96231b3b80d8
ASTMatchers: for-rangify loops. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220559 91177308-0d34-0410-b5e6-96231b3b80d8
ASTMatchers: Peel off a layer of indirection from true matcher. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220560 91177308-0d34-0410-b5e6-96231b3b80d8