SkTypeface_win_dw: populate_glyph_to_unicode uses lowest unichar BUG=chromium:538133 BUG=chromium:359065 Change-Id: I8208efc63579e0f1ebb77680beae2cd08cdba547 Reviewed-on: https://skia-review.googlesource.com/11681 Reviewed-by: Mike Klein <mtklein@chromium.org> Commit-Queue: Hal Canary <halcanary@google.com>