Merging r339128:

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r339128 | theraven | 2018-08-07 14:02:46 +0200 (Tue, 07 Aug 2018) | 8 lines

[objc-gnustep] Don't emit .guess ivar offset vars.

These were intended to allow non-fragile and fragile ABI code to be
mixed, as long as the fragile classes were higher up the hierarchy than
the non-fragile ones.  Unfortunately:

 - No one actually wants to do this.
 - Recent versions of Linux's run-time linker break it.
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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_70@339233 91177308-0d34-0410-b5e6-96231b3b80d8