src, branch vendor/llvm-libunwind-90

Vendor import of stripped LLVM libunwind trunk r366426 (just before the

2019-08-20T20:51:22+00:00

release_90 branch point):

https://llvm.org/svn/llvm-project/libunwind/trunk@366426

Vendor import of LLVM libunwind trunk r351319 (just before the

2019-03-08T22:14:20+00:00

release_80 branch point):
https://llvm.org/svn/llvm-project/libunwind/trunk@351319

Import LLVM libunwind snapshot revision 272680

2016-07-05T18:00:23+00:00

Significant upstream revisions:

260595: [AArch64] Fix libunwind build when using GNU assembler
270692: Introduce a native-only unwinder build.
270972: Disable cross-unwinding by default.
271004: [libunwind] Improve unwinder stack usage - II
272680: [libunwind] Improve unwinder stack usage - III

Obtained from:	https://llvm.org/svn/llvm-project/libunwind/trunk/

Import LLVM libunwind snapshot revision 256779

2016-01-04T21:30:54+00:00

From https://llvm.org/svn/llvm-project/libunwind/trunk/

Import LLVM libunwind snapshot revision 246528

2015-09-23T19:02:06+00:00

From https://llvm.org/svn/llvm-project/libunwind/trunk/