Sign-extension opcodes have been split into a separate proposal from
the main threads proposal, so switch them to their own target
feature. See:
https://github.com/WebAssembly/sign-extension-ops
llvm-svn: 322966
Add extending loads and constant offset patterns
A bit more refactoring of the tablegen to make the patterns fairly nice and
uniform between the regular and atomic loads.
Differential Revision: https://reviews.llvm.org/D38523
llvm-svn: 315022