Fixes #659: The create_stream() and create_event() methods of `co…

…ntext_t` are now `const`

Also, an indentation tweak.

src/cuda/api/context.hpp

@@ -577,14 +577,14 @@ class context_t {
 	/// regarding the parameters
 	stream_t create_stream(
 		bool                will_synchronize_with_default_stream,
-		stream::priority_t  priority = cuda::stream::default_priority);
+		stream::priority_t  priority = cuda::stream::default_priority) const;
 
 	/// Create a new event within this context; see @ref cuda::event::create() for details
 	/// regarding the parameters
 	event_t create_event(
 		bool uses_blocking_sync = event::sync_by_busy_waiting, // Yes, that's the runtime default
 		bool records_timing     = event::do_record_timings,
-		bool interprocess       = event::not_interprocess);
+		bool interprocess       = event::not_interprocess) const;
 
 	/// Create a new module of kernels and global memory regions within this context;
 	/// see also @ref cuda::module::create()

src/cuda/api/multi_wrapper_impls/context.hpp

@@ -297,16 +297,16 @@ inline device_t context_t::device() const
 }
 
 inline stream_t context_t::create_stream(
-bool                will_synchronize_with_default_stream,
-stream::priority_t  priority)
+	bool                will_synchronize_with_default_stream,
+	stream::priority_t  priority) const
 {
 	return stream::detail_::create(device_id_, handle_, will_synchronize_with_default_stream, priority);
 }
 
 inline event_t context_t::create_event(
 	bool uses_blocking_sync,
 	bool records_timing,
-	bool interprocess)
+	bool interprocess) const
 {
 	return cuda::event::detail_::create(
 		device_id_, handle_, do_not_hold_primary_context_refcount_unit,