Auto merge of #11103 - pcwalton:mac-font-matching, r=metajack

gfx: Map CSS `normal` font weight to Regular font weight on the Mac.

This series of commits fixes #9487, and improves the look of nytimes.com among others.

r? @metajack

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tests/wpt/metadata-css/css-text-3_dev/html/word-break-break-all-007.htm.ini

@@ -1,5 +0,0 @@
-[word-break-break-all-007.htm]
-  type: reftest
-  expected:
-    if os == "linux": PASS
-    FAIL

tests/wpt/metadata-css/css-text-3_dev/html/word-break-normal-hi-000.htm.ini

@@ -1,3 +1,5 @@
 [word-break-normal-hi-000.htm]
   type: reftest
-  expected: FAIL
+  expected:
+    if os == "linux": FAIL
+    PASS