[mlir][arith] Add arith::ConstantIntOp constructor (llvm#144638)

This PR adds a `build()` constructor for `ConstantIntOp` that takes in
an `APInt`.


Creating an `arith` constant value with an `APInt` currently requires a
structure like the following:
```c
b.create<arith::ConstantOp>(IntegerAttr::get(apintValue, 5));
```
In comparison, the`ConstantFloatOp` already has an `APFloat` constructor
which allows for the following:
```c
b.create<arith::ConstantFloatOp>(floatType, apfloatValue);
```
Thus, intuitively, it makes sense that a similar `ConstantIntOp`
constructor is made for `APInts` like so:
```c
b.create<arith::ConstantIntOp>(intType, apintValue);
```

Depends on llvm#144636

Author: ashjeong

mlir/include/mlir/Dialect/Arith/IR/Arith.h

@@ -65,6 +65,10 @@ class ConstantIntOp : public arith::ConstantOp {
   static void build(OpBuilder &builder, OperationState &result, Type type,
                     int64_t value);
 
+  /// Build a constant int op that produces an integer from an APInt
+  static void build(OpBuilder &builder, OperationState &result, Type type,
+                    const APInt &value);
+
   inline int64_t value() {
     return cast<IntegerAttr>(arith::ConstantOp::getValue()).getInt();
   }

mlir/lib/Dialect/Arith/IR/ArithOps.cpp

@@ -262,6 +262,12 @@ void arith::ConstantIntOp::build(OpBuilder &builder, OperationState &result,
                            builder.getIntegerAttr(type, value));
 }
 
+void arith::ConstantIntOp::build(OpBuilder &builder, OperationState &result,
+                                 Type type, const APInt &value) {
+  arith::ConstantOp::build(builder, result, type,
+                           builder.getIntegerAttr(type, value));
+}
+
 bool arith::ConstantIntOp::classof(Operation *op) {
   if (auto constOp = dyn_cast_or_null<arith::ConstantOp>(op))
     return constOp.getType().isSignlessInteger();