Changes

[msan] Support %ms in scanf.

Differential Revision: https://reviews.llvm.org/D85350

AMDGPU/GlobalISel: Enable s_{and|or}n2_{b32|b64} patterns

[AMDGPU] Correct missing sram-ecc target feature for gfx906

Differential Revision: https://reviews.llvm.org/D85476

BPF: fix libLLVMBPFCodeGen.so build failure

Buildbot reported a build failure when building shared
library libLLVMBPFCodeGen.so with unknown reference to
"createCFGSimplificationPass".

Commit 87cba434027b ("BPF: add a SimplifyCFG IR pass during
generic Scalar/IPO optimization") added an IR pass SimplifyCFG
by BPF target. The commit called function
createCFGSimplificationPass() defined in "Scalar" library.
Add this library in Target/BPF/LLVMBuild.txt so
shared library build can succeed.

[ELF] Change tombstone values to (.debug_ranges/.debug_loc) 1 and (other .debug_*) 0

tl;dr See D81784 for the 'tombstone value' concept. This patch changes our behavior to be almost the same as GNU ld (except that we also use 1 for .debug_loc):

* .debug_ranges & .debug_loc: 1 (LLD<11: 0+addend; GNU ld uses 1 for .debug_ranges)
* .debug_*: 0 (LLD<11: 0+addend; GNU ld uses 0; future LLD: -1)

We make the tweaks because:

1) The new tombstone is novel and needs more time to be adopted by consumers before it's the default.
2) The old (gold) strategy had problems with zero-length functions - so rather than going back that, we're going to the GNU ld strategy which doesn't have that problem.
3) One slight tweak to (2) is to apply the .debug_ranges workaround to .debug_loc for the same reasons it applies to debug_ranges - to avoid terminating lists early.

-----

http://lists.llvm.org/pipermail/llvm-dev/2020-July/143482.html

The tombstone value -1 in .debug_line caused problems to lldb (fixed by D83957;
will be included in 11.0.0) and breakpad (fixed by
https://crrev.com/c/2321300). It may potentially affects other DWARF consumers.

For .debug_ranges & .debug_loc: 1, an argument preferring 1 (GNU ld for .debug_ranges) over -2 is that:
```
{-1, -2}    <<< base address selection entry
{0, length} <<< address range
```
may create a situation where low_pc is greater than high_pc. So we use
1, the GNU ld behavior for .debug_ranges

For other .debug_* sections, there haven't been many reports. One issue is that
bloaty (src/dwarf.cc) can incorrectly count address ranges in .debug_ranges . To
reduce similar disruption, this patch changes the tombstone values to be similar to GNU ld.

This does mean another behavior change to the default trunk behavior. Sorry
about it. The default trunk behavior will be similar to release/11.x while we work on a transition plan for LLD users.

Reviewed By: dblaikie, echristo

Differential Revision: https://reviews.llvm.org/D84825

[NewPM][GuardWidening] Fix loop guard widening tests under NPM

Reviewed By: ychen, asbirlea

Differential Revision: https://reviews.llvm.org/D85394

[gn build] mac: use frameworks instead of libs where appropriate

As of GN 3028c6a426a4, the hack that transformed "libs" ending in
".framework" from -l arguments to -framework arguments has been removed.
Instead, "frameworks" must be used, and the toolchain must provide
support.

Differential Revision: https://reviews.llvm.org/D84219

GlobalISel: Implement lower for G_INSERT_VECTOR_ELT

Factor out common code from the iPhone/AppleTV/WatchOS simulator platform plugins. (NFC)

The implementation of these classes was copied & pasted from the
iPhone simulator plugin with only a handful of configuration
parameters substituted. This patch moves the redundant implementations
into the base class PlatformAppleSimulator.

Differential Revision: https://reviews.llvm.org/D85243