Changes

[lld][WebAssembly] Fix for weak undefined functions in -pie mode

This fixes two somewhat related issues.  Firstly we were never
generating imports for weak functions (even with the `import-functions`
policy for undefined symbols).  Adding a direct call to foo in the
`weak-undefined-pic.s` exposed a crash in the linker which this
change fixes.

Secondly we were failing to call `handleWeakUndefines` for the `-pie`
case which is PIC but doesn't set the undefined symbol policy to
`import-functions`.  With this change `-pie` binaries will by default
call `handleWeakUndefines` which generates the undefined stub handlers
for any weakly undefined symbols.

Fixes: https://github.com/emscripten-core/emscripten/issues/13337

Differential Revision: https://reviews.llvm.org/D95914

[knownbits] Preserve known bits for small shift recurrences

The motivation for this is that I'm looking at an example that uses shifts as induction variables. There's lots of other omissions, but one of the first I noticed is that we can't compute tight known bits. (This indirectly causes SCEV's range analysis to produce very poor results as well.)

Differential Revision: https://reviews.llvm.org/D96440

[mlir] detect integer overflow in debug mode

Rationale:
This computation failed ASAN for the following input
(integer overflow during 4032000000000000000 * 100):

  tensor<100x200x300x400x500x600x700x800xf32>

This change adds a simple overflow detection during
debug mode (which we run more regularly than ASAN).
Arguably this is an unrealistic tensor input, but
in the context of sparse tensors, we may start to
see cases like this.

Bug:
https://bugs.llvm.org/show_bug.cgi?id=49136

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D96530

[Polly] Hide IslScheduleOptimizer implementation from header. NFC.

These are implementation details of the IslScheduleOptimizer pass
implementation and not use anywhere else. Hence, we can move them to the
cpp file and into an anonymous namespace.

Only getPartialTilePrefixes is, aside from the pass itself, used
externally (by the ScheduleOptimizerTest) and moved into the polly
namespace.

Partially Revert "scan-view: Remove Reporter.py and associated AppleScript files"

This reverts some of commit dbb01536f6f49fa428f170e34466072ef439b3e9.

The Reporter module was still being used by the ScanView.py module and deleting
it caused scan-view to fail.  This commit adds back Reporter.py but removes the
code the references the AppleScript files which were removed in
dbb01536f6f49fa428f170e34466072ef439b3e9.

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D96367

DebugInfo/Symbolize: Don't differentiate function/data symbolization

Before d08bd13ac8a560c4645e17e192ca07e1bdcd2895, only `SymbolRef::ST_Function`
symbols were used for .symtab symbolization. That commit added a `"DATA"` mode
to llvm-symbolizer which used `SymbolRef::ST_Data` symbols for symbolization.

Since function and data symbols have different addresses, we don't need to
differentiate the two modes. This patches unifies the two modes to simplify
code.

`"DATA"` is used by `compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_libcdep.cpp`.
`check-hwasan` and `check-tsan` have runtime tests.

Differential Revision: https://reviews.llvm.org/D96322

[GlobalISel] Fix sext_inreg(load) combine to not move the originating load.

The builder was using the extend user as the insertion point, which meant that
we were incorrectly "moving" the load from its original position, and therefore
could violate memory operation ordering.

Fix bitcode decoder error in "Encode alignment attribute for `atomicrmw`"

The wrong record field number was being used in bitcode decoding,
which broke a self-hosted LTO build. (Yet, somehow, this _doesn't_
seem to have broken simple bitcode encode/decode roundtrip tests, and
I'm not sure why...)

Fixes commit d06ab79816785fa362e7d96d7a398bea8064cba7