[SR-1649] Handle renaming a variable to a function

[belkadan]

Previous ID	SR-1649
Radar	rdar://problem/26563343
Original Reporter	@belkadan
Type	Bug
Status	Closed
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug, DiagnosticsQoI
Assignee	@belkadan
Priority	Medium

md5: b8cd30cbca207a91354bd4f452864a68

Issue Description:

This code:

@available(*, unavailable, renamed: "Foo.new()")
public var old: Int { fatalError() }

func test() {
  let x = old
}

produces this diagnostic

<stdin>:7:11: error: 'old' has been replaced by 'Foo.new()'
  let x = old
          ^~~
          Foo.new

We should get it to add the parens as well.

[belkadan]

The code that handles all renaming is in MiscDiagnostics.cpp. We have special handling for the function-to-variable case via the "getter:" syntax in the renamed parameter, but nothing for the other way around.

[belkadan]

Harlan implemented this in a99ca85.

[belkadan]

…and it turns out that failed to consider this case:

@available(*, unavailable, renamed: "Foo.new()")
func test() {}

func use() {
  let x = test
  x()
}

[belkadan]

Reimplemented in #4938

[belkadan]

And merged to swift-3.0-branch in #4979