[CIR][NFC] Clean up constant op comments (llvm#162142)

Author: xlauko

clang/include/clang/CIR/Dialect/IR/CIROps.td

@@ -278,22 +278,22 @@ def CIR_PtrStrideOp : CIR_Op<"ptr_stride", [
 def CIR_ConstantOp : CIR_Op<"const", [
   ConstantLike, Pure, AllTypesMatch<["value", "res"]>
 ]> {
-  let summary = "Defines a CIR constant";
+  let summary = "Create a CIR constant from a literal attribute";
   let description = [{
     The `cir.const` operation turns a literal into an SSA value. The data is
     attached to the operation as an attribute.
 
     ```mlir
-      %0 = cir.const 42 : i32
-      %1 = cir.const 4.2 : f32
-      %2 = cir.const nullptr : !cir.ptr<i32>
+      %0 = cir.const #cir.int<4> : !u32i
+      %1 = cir.const #cir.fp<1.500000e+00> : !cir.float
+      %2 = cir.const #cir.ptr<null> : !cir.ptr<!void>
     ```
   }];
 
   let arguments = (ins TypedAttrInterface:$value);
   let results = (outs CIR_AnyType:$res);
 
-  let assemblyFormat = "attr-dict $value";
+  let assemblyFormat = "$value attr-dict";
 
   let hasVerifier = 1;