[5.7] Revert "[TypeChecker] Adjust Double<->CGFloat conversion to always pr…

[xedin]

…eserve its location"

These changes broke a case where conversion is used in a literal array
element position passed as an argument to a call i.e.:

enum E {
  case test([CGFloat])
}

struct Container {
  var prop: E
}

struct Point {
  var x: Double
  var y: Double
}

func test(cont: inout Container, point: Point) {
  cont.prop = .test([point.x, point.y])
}

Reverting only from 5.7 and going to fix the issue on main.

Resolves: rdar://96469597

This reverts commit 7777e3a.

[xedin]

@swift-ci please test