NFC: Refactor block signature conversion to not erase the original arguments.

This refactors the implementation of block signature(type) conversion to not insert fake cast operations to perform the type conversion, but to instead create a new block containing the proper signature. This has the benefit of enabling the use of pre-computed analyses that rely on mapping values. It also leads to a much cleaner implementation overall. The major user facing change is that applySignatureConversion will now replace the entry block of the region, meaning that blocks generally shouldn't be cached over calls to applySignatureConversion.

PiperOrigin-RevId: 280226936

2 files changed, 2 insertions, 2 deletions

diff --git a/mlir/test/Transforms/test-legalizer-full.mlir b/mlir/test/Transforms/test-legalizer-full.mlir
index 0b658688ba1..d0fc4c9bc89 100644
--- a/mlir/test/Transforms/test-legalizer-full.mlir
+++ b/mlir/test/Transforms/test-legalizer-full.mlir
@@ -13,7 +13,7 @@ func @multi_level_mapping() {
 // CHECK-LABEL: func @dropped_region_with_illegal_ops
 func @dropped_region_with_illegal_ops() {
   // CHECK-NEXT: test.return
-  "test.drop_op"() ({
+  "test.drop_region_op"() ({
     %ignored = "test.illegal_op_f"() : () -> (i32)
     "test.return"() : () -> ()
   }) : () -> ()
diff --git a/mlir/test/Transforms/test-legalizer.mlir b/mlir/test/Transforms/test-legalizer.mlir
index 1e563257902..efb59b08e3e 100644
--- a/mlir/test/Transforms/test-legalizer.mlir
+++ b/mlir/test/Transforms/test-legalizer.mlir
@@ -91,7 +91,7 @@ func @remap_cloned_region_args() {
 func @remap_drop_region() {
   // CHECK-NEXT: return
   // CHECK-NEXT: }
-  "test.drop_op"() ({
+  "test.drop_region_op"() ({
     ^bb1(%i0: i64, %unused: i16, %i1: i64, %2: f32):
       "test.invalid"(%i0, %i1, %2) : (i64, i64, f32) -> ()
   }) : () -> ()