Remove `builtins.` from error messages

[JelleZijlstra]

Our error messages would be a bit more concise if we removed the builtins. part from type output, and perhaps typing. too. This would make error messages match up more closely with runtime syntax.

For example, we currently output None as builtins.None, which is a syntax error at runtime. Just outputting None would be more clear.

[ilevkivskyi]

I think they should be already removed from almost everywhere (if not, this is a bug). The only place that shows all names full is the error for overloads. I think this is the one we need to fix first.

[JelleZijlstra]

reveal_type also outputs builtins..

[ilevkivskyi]

Yes, but TBH I think overloads are still more important, reveal_type is kind of debugging tool so it is more expected to show some verbose output.

[JelleZijlstra]

There's a couple of others:

unit/check-bound.test:x = None # type: G[str] # E: Type argument "builtins.str" of "G" must be a subtype of "__main__.A"
unit/check-bound.test:class D3(C[str]): pass # E: Type argument "builtins.str" of "C" must be a subtype of "__main__.A"
unit/check-classes.test:tmp/foo.pyi:5: error: Invalid signature "def (foo.C, Any, Any) -> builtins.int"
unit/check-classes.test:main:6: error: Invalid signature "def (__main__.C, builtins.str, builtins.str) -> __main__.C"
unit/check-classes.test:main:6: error: Invalid signature "def (__main__.C, builtins.str, builtins.str) -> __main__.C"
unit/check-classes.test:    def __setattr__(self, name: int, value: int) -> None: ...  # E: Invalid signature "def (__main__.C, builtins.int, builtins.int)"
unit/check-classes.test:NT = NewType('NT', N) # E: Argument 2 to NewType(...) must be subclassable (got TypedDict('__main__.N', {'x': builtins.int}))
unit/check-classes.test:main:4: error: t: builtins.str
unit/check-classes.test:main:4: error: y: builtins.float
unit/check-expressions.test:main:4: error: x: builtins.int
unit/check-expressions.test:main:4: error: y: builtins.int
unit/check-expressions.test:main:4: error: z: builtins.int
unit/check-functions.test:main:4: error: a: builtins.int
unit/check-functions.test:main:4: error: b: builtins.int
unit/check-functions.test:main:6: error: a: builtins.int
unit/check-functions.test:main:6: error: b: builtins.int
unit/check-functions.test:main:6: error: c: builtins.int
unit/check-functions.test:main:9: error: a: builtins.float
unit/check-modules.test:tmp/has_getattr.pyi:1: error: Invalid signature "def (builtins.int, builtins.str) -> builtins.str"
unit/check-namedtuple.test:yb: G[int] # E: Type argument "builtins.int" of "G" must be a subtype of "Tuple[builtins.int, fallback=__main__.M]"
unit/check-selftype.test:    def foo(self: T) -> T:   # E: The erased type of self 'builtins.str' is not a supertype of its class '__main__.A'
unit/check-selftype.test:    def cfoo(cls: Type[T]) -> T:  # E: The erased type of self 'Type[builtins.str]' is not a supertype of its class 'Type[__main__.A]'
unit/check-typeddict.test:yb: G[int] # E: Type argument "builtins.int" of "G" must be a subtype of "TypedDict('__main__.M', {'x': builtins.int})"
unit/check-unions.test:(e1, e2) = e  # E: 'builtins.int' object is not iterable
unit/check-unions.test:x, y = bad # E: 'builtins.int' object is not iterable \
unit/check-unions.test:           # E: 'builtins.str' object is not iterable

[ilevkivskyi]

Oh wow, this would be quite some work to clean-up. Also this needs to switch to using double quotes probably "...".