Only return macros that are valid in their current position, ie. an
attached macro is not valid on a nominal.
Also return freestanding expression macros in code block item position
and handle the new freestanding code item macros.
Resolves rdar://105563583.
When parameter is added by addSimpleNamedParameter(), the type name
doesn't exist. Instead of printing empty strings, use short version of
editor placeholders.
rdar://83904268
`CodeCompletioString::getName()` was used only as the sorting keys in
`CodeCompletionContext::sortCompletionResults()` which is effectively
deprecated. There's no reason to check them in `swift-ide-test`. Instead,
check `printCodeCompletionResultFilterName()` that is actually used for
filtering.
To describe fine grained priorities.
Introduce 'CodeCompletionFlair' that is a set of more descriptive flags for
prioritizing completion items. This aims to replace '
SemanticContextKind::ExpressionSpecific' which was a "catch all"
prioritization flag.
