[cairo] perf: long dashed lines

[Vladimir Vukicevic]

Sorry, that was a bogus profile -- had the wrong optimization  
options.  Here's the right one:

     Self      Total
	0.0%	96.6%	libcairo.2.dylib	     cairo_stroke_preserve	
	0.0%	96.6%	libcairo.2.dylib	      _cairo_gstate_stroke	
	0.0%	96.6%	libcairo.2.dylib	       _cairo_surface_stroke	
	0.0%	96.5%	libcairo.2.dylib	        _cairo_surface_fallback_stroke	
	0.0%	91.9%	libcairo.2.dylib	         _cairo_path_fixed_stroke_to_traps	
	0.0%	91.8%	libcairo.2.dylib	          _cairo_path_fixed_interpret	
	23.7%	91.8%	libcairo.2.dylib	           _cairo_stroker_line_to_dashed	
	2.5%	59.4%	libcairo.2.dylib	            _cairo_stroker_add_sub_edge	
	27.8%	33.1%	libcairo.2.dylib	             _compute_face	
	4.6%	4.6%	libcairo.2.dylib	               
cairo_matrix_transform_distance	
	0.7%	0.7%	libcairo.2.dylib	               
_cairo_matrix_compute_determinant	
	9.2%	23.8%	libcairo.2.dylib	              
_cairo_traps_tessellate_convex_quad	
	0.0%	0.0%	libcairo.2.dylib	              
_cairo_traps_add_trap_from_points	
	4.0%	4.8%	libcairo.2.dylib	            _cairo_stroker_add_leading_cap	
	2.6%	2.6%	libcairo.2.dylib	            cairo_matrix_transform_distance	
	1.2%	1.2%	libcairo.2.dylib	            _cairo_stroker_add_cap	
	0.0%	0.0%	libcairo.2.dylib	            _compute_face	
	0.0%	0.0%	libcairo.2.dylib	            
_cairo_rectilinear_stroker_close_path	
	0.0%	0.0%	libcairo.2.dylib	           cairo_matrix_transform_distance	
	0.0%	0.0%	libcairo.2.dylib	            
_cairo_rectilinear_stroker_line_to	
	0.0%	0.1%	libcairo.2.dylib	          _cairo_pen_init	
	0.0%	0.0%	libcairo.2.dylib	          _cairo_pen_fini	
	0.0%	0.0%	libSystem.B.dylib	          free	
	0.0%	4.5%	libcairo.2.dylib	         _clip_and_composite_trapezoids	
	0.0%	0.0%	libcairo.2.dylib	         _cairo_traps_fini	
	0.0%	0.0%	libcairo.2.dylib	         _cairo_clip_intersect_to_rectangle	
	0.0%	0.0%	libcairo.2.dylib	         _cairo_surface_get_extents	
	0.0%	0.0%	libcairo.2.dylib	         _cairo_traps_extract_region	
	0.0%	0.0%	libcairo.2.dylib	         _cairo_region_get_extents	
	0.0%	0.1%	libcairo.2.dylib	        cairo_pattern_destroy	
	0.0%	0.0%	libcairo.2.dylib	         
_cairo_surface_copy_pattern_for_destination	
	0.0%	0.0%	libcairo.2.dylib	        _clip_and_composite_trapezoids	
	0.0%	0.0%	libcairo.2.dylib	        
_cairo_gstate_copy_transformed_pattern	
	0.0%	0.0%	libcairo.2.dylib	       _cairo_surface_set_clip	
	0.0%	0.0%	libcairo.2.dylib	        
_cairo_surface_copy_pattern_for_destination