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emaste
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svn:date
V 27
2019-12-27T16:28:43.951316Z
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V 407
src.opts.mk: switch LLVM_LIBUNWIND to opt-out

PowerPC switched to LLVM_LIBUNWIND along with the switch to Clang/LLVM
in r356111.  This leaves only 32-bit Arm and sparc64 not using LLVM's
unwinder, so switch the sense to opt-out.

I elected to list the individual arm MACHINE_ARCHs so future changes
are more clear if LLVM_LIBUNWIND is enabled for one or two but not all
32-bit Arm targets (see PR 233664).

END