Shapes::idx examples are all not typechecked, some invalid

[fredemmott]

Please complete the information below:

Where is the problem?

The entire example.

What is the problem?

The typechecker doesn't look at pseudomains, and all the code is in pseudomains; a lot of these examples are not legal Hack code.

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Please don't change anything below this point.

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• Build ID: 2016-08-15T18:49:04+0000:e756f9162e96b867a06b2805e03056a63fc17931:2b940b7ef772640b5980b78c645f89cbd216d81f
• Page requested: /hack/reference/class/HH.Shapes/idx/
• Page requested at: Sun, 02 Oct 2016 03:47:00 +0000
• Controller: APIMethodPageController

[fredemmott]

They're now in a pseudomain, but this is still invalid and should raise a type error:

+  // The key 'z' doesn't exist in $point so our explicit default 0 is returned
 -var_dump(Shapes::idx($point, 'z', 0));         +  var_dump(Shapes::idx($point, 'z', 0));

[fredemmott]

Though I guess that's partially a dupe of #375, the change commit you made for this issue should cause test failures