Auto merge of #14047 - mskrzypkows:getElementsByTagName, r=nox

fix getElementsByTagName()

<!-- Please describe your changes on the following line: -->
Improved implementation of getElementsByTagName() in Document, properly pass 3 cases of https://dom.spec.whatwg.org/#concept-getelementsbytagname

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix  #11596 (github issue number if applicable).

<!-- Either: -->
- [x] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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tests/wpt/metadata/dom/nodes/Document-getElementsByTagName-xhtml.xhtml.ini

@@ -3,18 +3,8 @@
   [HTML element with uppercase tag name matches in XHTML documents]
     expected: FAIL
 
-  [Element in non-HTML namespace, prefix, lowercase name]
-    expected: FAIL
-
-  [Element in non-HTML namespace, prefix, uppercase name]
-    expected: FAIL
-
   [Element in HTML namespace, no prefix, non-ascii characters in name]
     expected: FAIL
 
   [Element in HTML namespace, prefix, non-ascii characters in name]
     expected: FAIL
-
-  [Element in non-HTML namespace, prefix, non-ascii characters in name]
-    expected: FAIL
-

tests/wpt/metadata/dom/nodes/Document-getElementsByTagName.html.ini

@@ -2,16 +2,3 @@
   type: testharness
   [Shouldn't be able to set unsigned properties on a HTMLCollection (strict mode)]
     expected: FAIL
-
-  [Element in non-HTML namespace, prefix, lowercase name]
-    expected: FAIL
-
-  [Element in non-HTML namespace, prefix, uppercase name]
-    expected: FAIL
-
-  [Element in HTML namespace, prefix, non-ascii characters in name]
-    expected: FAIL
-
-  [Element in non-HTML namespace, prefix, non-ascii characters in name]
-    expected: FAIL
-

tests/wpt/metadata/dom/nodes/Element-getElementsByTagName.html.ini

@@ -2,16 +2,3 @@
   type: testharness
   [Shouldn't be able to set unsigned properties on a HTMLCollection (strict mode)]
     expected: FAIL
-
-  [Element in non-HTML namespace, prefix, lowercase name]
-    expected: FAIL
-
-  [Element in non-HTML namespace, prefix, uppercase name]
-    expected: FAIL
-
-  [Element in HTML namespace, prefix, non-ascii characters in name]
-    expected: FAIL
-
-  [Element in non-HTML namespace, prefix, non-ascii characters in name]
-    expected: FAIL
-

tests/wpt/metadata/dom/nodes/case.html.ini

@@ -1,17 +0,0 @@
-[case.html]
-  type: testharness
-  [getElementsByTagName a:abc]
-    expected: FAIL
-
-  [getElementsByTagName a:Abc]
-    expected: FAIL
-
-  [getElementsByTagName a:ABC]
-    expected: FAIL
-
-  [getElementsByTagName a:ä]
-    expected: FAIL
-
-  [getElementsByTagName a:Ä]
-    expected: FAIL
-