Make some WebGL parameters non-optional (fixes #8753)

Those parameters aren't optional in the current spec.

The test element-array-buffer-delete-recreate.html now fails because we don't
actually implement gl.getParameter(gl.CURRENT_PROGRAM).

tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/buffers/element-array-buffer-delete-recreate.html.ini

@@ -1,8 +1,12 @@
 [element-array-buffer-delete-recreate.html]
   type: testharness
+  expected: ERROR
   [WebGL test #0: getError expected: NO_ERROR. Was INVALID_ENUM : no errors from draw]
     expected: FAIL
 
   [WebGL test #1: at (0, 0) expected: 0,255,0,255 was 0,0,0,0]
     expected: FAIL
 
+  [WebGL test #0: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
+    expected: FAIL
+

tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/canvas/drawingbuffer-hd-dpi-test.html.ini

@@ -1,5 +1,6 @@
 [drawingbuffer-hd-dpi-test.html]
   type: testharness
+  expected: ERROR
   [WebGL test #5: at (28, 12) expected: 0,255,0,255 was 0,0,0,0]
     expected: FAIL
 
@@ -45,3 +46,6 @@
   [WebGL test #50: gl.getError() should be 0. Was 1280.]
     expected: FAIL
 
+  [WebGL test #5: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
+    expected: FAIL
+

tests/wpt/mozilla/meta/webgl/conformance-2.0.0/conformance2/transform_feedback/unwritten-output-defaults-to-zero.html.ini

@@ -1,7 +1,11 @@
 [unwritten-output-defaults-to-zero.html]
+  expected: ERROR
   [WebGL test #1: Fail to set up the program]
     expected: FAIL
 
   [WebGL test #2: Fail to set up the program]
     expected: FAIL
 
+  [WebGL test #1: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
+    expected: FAIL
+