Merge pull request swiftlang#19527 from slavapestov/add-regression-test

Add regression test for fixed crasher

Author: slavapestov

test/Constraints/valid_pointer_conversions.swift

@@ -3,3 +3,10 @@
 func foo(_ a: [[UInt8]], _ p: [UnsafeRawPointer]) {
   foo(a, a) // expect-warning {{all paths through this function will call itself}}
 }
+
+// rdar://problem/44658089
+func takesPtr(_: UnsafePointer<UInt8>) {}
+
+func givesPtr(_ str: String) {
+    takesPtr(UnsafePointer(str))
+}