tree 0831dc33ec1eed8cdf659f077f2e88abb7c44952
parent 5dceabfe017f72812966261ba8326c83d709729e
author Sam Elliott <selliott@lowrisc.org> 1571061613 +0000
committer Sam Elliott <selliott@lowrisc.org> 1571061613 +0000

[RISCV] enable LTO support, pass some options to linker.

Summary:
1. enable LTO need to pass target feature and abi to LTO code generation
   RISCV backend need the target feature to decide which extension used in
   code generation.
2. move getTargetFeatures to CommonArgs.h and add ForLTOPlugin flag
3. add general tools::getTargetABI in CommonArgs.h because different target uses different
   way to get the target ABI.

Patch by Kuan Hsu Chen (khchen)

Reviewers: lenary, lewis-revill, asb, MaskRay

Reviewed By: lenary

Subscribers: hiraditya, dschuff, aheejin, fedor.sergeev, mehdi_amini, inglorion, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, rkruppe, PkmX, jocewei, psnobl, benna, Jim, lenary, s.egerton, pzheng, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67409

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374774 91177308-0d34-0410-b5e6-96231b3b80d8