Add margins test.

This test is also approx'd to 1px due to the same issue where heights are off by one.

core/tests/regression_tests.rs

@@ -212,6 +212,7 @@ swf_tests_approx! {
     (stage_object_properties_swf6, "avm1/stage_object_properties_swf6", 4, 0.051),
     (movieclip_getbounds, "avm1/movieclip_getbounds", 1, 0.051),
     (edittext_letter_spacing, "avm1/edittext_letter_spacing", 1, 1.0),
+    (edittext_margins, "avm1/edittext_margins", 1, 1.0),
 }
 
 /// Wrapper around string slice that makes debug output `{:?}` to print string same way as `{}`.

core/tests/swfs/avm1/edittext_margins/output.txt

@@ -0,0 +1,25 @@
+//Creating left aligned indented text w/ wordwrap, multiline & long text
+//field.textWidth
+370
+//field.textHeight
+75
+//Creating center aligned indented text w/ wordwrap, multiline & long text
+//field.textWidth
+367
+//field.textHeight
+75
+//Creating right aligned indented text w/ wordwrap, multiline & long text
+//field.textWidth
+367
+//field.textHeight
+75
+//Creating justified indented text w/ wordwrap, multiline & long text
+//field.textWidth
+367
+//field.textHeight
+75
+//Creating marginless text w/ wordwrap, multiline & long text
+//field.textWidth
+376
+//field.textHeight
+60