[StableHLO][CHLO] Port CHLO decomposition patterns

These are ported from the mlir-hlo project. For more context, see the
initial import: iree-org#12957.

The biggest difference it the removal of most FileCheck CHECK lines in
tests. MHLO hardcoded thousands lines of exact decomposition sequences
that fell apart after due to different canonicalizations and folds.
Without a script to regenerate these CHECKs, these tests were not
maintanable and I decided to drop them. Now we only check that the
dialect conversion succeeded.

Other notable differences to the MHLO implementation:
-  Ported some utility functions and tablegen defs.
-  New `chlo.tan` lowering, since StableHLO does not provide a tan op.

Issue: iree-org#13803

compiler/src/iree/compiler/InputConversion/StableHLO/BUILD.bazel

@@ -42,6 +42,23 @@ iree_compiler_cc_library(
     ],
 )
 
+iree_gentbl_cc_library(
+    name = "CHLODecompositionPatterns",
+    tbl_outs = [
+        (
+            ["--gen-rewriters"],
+            "CHLODecompositionPatterns.h.inc",
+        ),
+    ],
+    tblgen = "@llvm-project//mlir:mlir-tblgen",
+    td_file = "CHLODecompositionPatterns.td",
+    deps = [
+        "@llvm-project//mlir:ShapeTdFiles",
+        "@mlir-hlo//stablehlo:chlo_ops_td_files",
+        "@mlir-hlo//stablehlo:stablehlo_ops_td_files",
+    ],
+)
+
 iree_compiler_cc_library(
     name = "StableHLOLegalization",
     srcs = [
@@ -66,6 +83,7 @@ iree_compiler_cc_library(
         "VerifyCompilerInputLegality.cpp",
     ],
     deps = [
+        ":CHLODecompositionPatterns",
         ":PassHeaders",
         "//compiler/src/iree/compiler/Dialect/Flow/IR",
         "//compiler/src/iree/compiler/Dialect/Util/IR",