[5.5][Async Refactoring] Get semantics providing expr to decide if call is to completion handler

[ahoppen]

• Explanation: Use getSemanticsProvidingExpr to decide whether an expression is a call to a completion handler. This resolves an issue where a completion handler would not be converted if it was wrapped in parenthesis
• Scope: Async refactoring of calls that are wrapped in an identity expression like parentheses or a trailing .self
• Risk: Low
• Testing: Added regression test
• Issue: rdar://78011350
• Reviewer: @hamishknight (Hamish Knight) on original PR [Async Refactoring] Get semantics providing expr to decide if call is to completion handler #38261

Example

Orignal code

func test(_ completion: (String?, Error?) -> Void) {
  return (completion("", nil))
}

Old Refactoring Result

func test() async throws -> String {
  return (<#completion#>("", nil))
}

New Refactoring Result

func test() async throws -> String {
  return ""
}

[ahoppen]

@swift-ci Please test

[ahoppen]

Windows failures is unrelated.