expand-large-divrem cannot handle vector types.
If overly large vector element types survive into
isel, they will likely be scalarized there, but since
isel cannot handle scalar integer types of that size,
it will assert.

Handle vector types in expand-large-divrem by
scalarizing them and then expanding the scalar type
operation. For large vectors, this results in a
*massive* code expansion, but it's better than
asserting.

This reverts commit 6bf1b4e8e0776e6f27013434d8b632016ccc795c.

Requiring a triple does not require moving these to a codegen test directory.
Move these to an x86 specific subdirectory of a transforms test.

Also remove new-pass-manager version of ExpandLargeDivRem because there is no way
yet to access TargetLowering in the new pass manager.

Differential Revision: https://reviews.llvm.org/D133691

So we can't use ctlz in poison-producing mode

This reverts commit 4aed09868b5a51a29aade11d9d412c3313310f29.

So we can't use ctlz in poison-producing mode

Adds a pass ExpandLargeDivRem to expand div/rem instructions
with more than 128 bits into a loop computing that value.

As discussed on https://reviews.llvm.org/D120327, this approach has the advantage
that it is independent of the runtime library. This also helps the clang driver,
which otherwise would need to understand enough about the runtime library
to know whether to allow _BitInts with more than 128 bits.

Targets are still free to disable this pass and instead provide a faster
implementation in a runtime library.

Fixes https://github.com/llvm/llvm-project/issues/44994

Differential Revision: https://reviews.llvm.org/D126644