Differential Revision: https://reviews.llvm.org/D81858

This reverts commit 32c757e4.

Broke the build bot:

******************** TEST 'MLIR :: Examples/standalone/test.toy' FAILED ********************
[...]
/tmp/ci-KIMiRFcVZt/lib/libMLIRLinalgToLLVM.a(LinalgToLLVM.cpp.o): In function `(anonymous namespace)::ConvertLinalgToLLVMPass::runOnOperation()':
LinalgToLLVM.cpp:(.text._ZN12_GLOBAL__N_123ConvertLinalgToLLVMPass14runOnOperationEv+0x100): undefined reference to `mlir::populateExpandTanhPattern(mlir::OwningRewritePatternList&, mlir::MLIRContext*)'

Summary:
Add a pattern for expanding tanh op into exp form.
A `tanh` is expanded into:
   1) 1-exp^{-2x} / 1+exp^{-2x}, if x => 0
   2) exp^{2x}-1 / exp^{2x}+1  , if x < 0.

Differential Revision: https://reviews.llvm.org/D81618

Generally:
1) don't use target_link_libraries() and add_mlir_library() on the same target, use LINK_LIBS PUBLIC instead.
2) don't use LINK_LIBS to specify LLVM libraries.  Use LINK_COMPONENTS instead
3) no need to link against LLVMSupport.  We pull it in by default.

Differential Revision: https://reviews.llvm.org/D80076

Without this LLVM_LINK_LLVM_DYLIB is broken

Differential Revision: https://reviews.llvm.org/D80074

Conversion/ folders were originally intended to store patterns for
DialectA->DialectB conversions that depend on both dialects and do not
conceptually belong to either of the dialects. As such, DialectA->DialectA
conversion does not make sense under Conversion/ and should rather live with
the dialect it operates on.

Differential Revision: https://reviews.llvm.org/D79569

Summary: This fixes shared lib build.

Differential Revision: https://reviews.llvm.org/D79403

Adding this pattern reduces code duplication. There is no need to have a
custom implementation for lowering to llvm.cmpxchg.

Differential Revision: https://reviews.llvm.org/D78753