tint: Rename ProgramBuilder::Construct() to Call()

Once all ast::Type derived classes are removed, there will be no
distinction between a type initializer / conversion and a function call.

Bug: tint:1810
Change-Id: Ic10fd1a0364a564d24dbe2499af0f1424641596c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/118980
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@chromium.org>

src/tint/transform/direct_variable_access.cc

@@ -574,7 +574,7 @@ struct DirectVariableAccess::State {
                      ->Type()
                      ->UnwrapRef()
                      ->IsAnyOf<type::U32, type::AbstractInt>()) {
-                expr = b.Construct(b.ty.u32(), expr);
+                expr = b.Call<u32>(expr);
             }
         }
 
@@ -937,7 +937,7 @@ struct DirectVariableAccess::State {
                         dyn_idx_args.Push(BuildDynamicIndex(dyn_idx, /* cast_to_u32 */ true));
                     }
                     // Construct the dynamic index array, and push as an argument.
-                    new_args.Push(b.Construct(dyn_idx_arr_ty, std::move(dyn_idx_args)));
+                    new_args.Push(b.Call(dyn_idx_arr_ty, std::move(dyn_idx_args)));
                 }
             }