[SelectionDAG] Extract [US]MULO expansion into TL method; NFC
In preparation for supporting vector expansion.
Add an isPostTypeLegalization flag to makeLibCall(), because this
expansion relies on the legalized form using MERGE_VALUES. Drop
the corresponding variant of ExpandLibCall, which is no longer used.
Differential Revision: https://reviews.llvm.org/D58006
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354226 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed