[mlir][complex] Allow integer element types in `complex.constant` ops (#74564)

The op used to support only float element types. This was inconsistent
with `ConstantOp::isBuildableWith`, which allows integer element types.
The complex type allows any float/integer element type.

Note: The other complex dialect ops do not support non-float element
types yet. The main purpose of this change to fix
`Tensor/canonicalize.mlir`, which is currently failing when verifying
the IR after each pattern application (#74270).

```
within split at mlir/test/Dialect/Tensor/canonicalize.mlir:231 offset :8:15: error: 'complex.constant' op result #0 must be complex type with floating-point elements, but got 'complex<i32>'
  %complex1 = tensor.extract %c1[] : tensor<complex<i32>>
              ^
within split at mlir/test/Dialect/Tensor/canonicalize.mlir:231 offset :8:15: note: see current operation: %0 = "complex.constant"() <{value = [1 : i32, 2 : i32]}> : () -> complex<i32>
"func.func"() <{function_type = () -> tensor<3xcomplex<i32>>, sym_name = "extract_from_elements_complex_i"}> ({
  %0 = "complex.constant"() <{value = [1 : i32, 2 : i32]}> : () -> complex<i32>
  %1 = "arith.constant"() <{value = dense<(3,2)> : tensor<complex<i32>>}> : () -> tensor<complex<i32>>
  %2 = "arith.constant"() <{value = dense<(1,2)> : tensor<complex<i32>>}> : () -> tensor<complex<i32>>
  %3 = "tensor.extract"(%1) : (tensor<complex<i32>>) -> complex<i32>
  %4 = "tensor.from_elements"(%0, %3, %0) : (complex<i32>, complex<i32>, complex<i32>) -> tensor<3xcomplex<i32>>
  "func.return"(%4) : (tensor<3xcomplex<i32>>) -> ()
}) : () -> ()
```

1 files changed, 6 insertions, 4 deletions

diff --git a/mlir/lib/Dialect/Complex/IR/ComplexOps.cpp b/mlir/lib/Dialect/Complex/IR/ComplexOps.cpp
index 6d87067..5529dcc 100644
--- a/mlir/lib/Dialect/Complex/IR/ComplexOps.cpp
+++ b/mlir/lib/Dialect/Complex/IR/ComplexOps.cpp
@@ -58,10 +58,12 @@ LogicalResult ConstantOp::verify() {
   }
 
   auto complexEltTy = getType().getElementType();
-  auto re = llvm::dyn_cast<FloatAttr>(arrayAttr[0]);
-  auto im = llvm::dyn_cast<FloatAttr>(arrayAttr[1]);
-  if (!re || !im)
-    return emitOpError("requires attribute's elements to be float attributes");
+  if (!isa<FloatAttr, IntegerAttr>(arrayAttr[0]) ||
+      !isa<FloatAttr, IntegerAttr>(arrayAttr[1]))
+    return emitOpError(
+        "requires attribute's elements to be float or integer attributes");
+  auto re = llvm::dyn_cast<TypedAttr>(arrayAttr[0]);
+  auto im = llvm::dyn_cast<TypedAttr>(arrayAttr[1]);
   if (complexEltTy != re.getType() || complexEltTy != im.getType()) {
     return emitOpError()
            << "requires attribute's element types (" << re.getType() << ", "