[SVG -> OTF Converter] Glyphs get clipped weirdly

[SVG -> OTF Converter] Glyphs get clipped weirdly
https://bugs.webkit.org/show_bug.cgi?id=137095

Reviewed by Antti Koivisto.

The Adobe CFF spec doesn't actually tell you how to serialize a
"FontBBox." After trial and error, it seems to be (x, y, width,
height).

Test: svg/text/kerning.svg
      svg/W3C-SVG-1.1/fonts-kern-01-t.svg

* svg/SVGToOTFFontConversion.cpp:
(WebCore::SVGToOTFFontConverter::appendHEADTable):
(WebCore::SVGToOTFFontConverter::appendCFFTable):
(WebCore::SVGToOTFFontConverter::appendVHEATable):
(WebCore::CFFBuilder::CFFBuilder):
(WebCore::SVGToOTFFontConverter::transcodeGlyphPaths):
(WebCore::SVGToOTFFontConverter::processGlyphElement):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@178647 268f45cc-cd09-0410-ab3c-d52691b4dbfc