Merge remote-tracking branch 'origin/master' into master-next

Author: swift-ci

docs/ABI/Mangling.rst

@@ -9,7 +9,7 @@ Mangling
 --------
 ::
 
-  mangled-name ::= '_S' global
+  mangled-name ::= '$S' global
 
 All Swift-mangled names begin with this prefix.
 

test/stdlib/Metal.swift

@@ -1,5 +1,5 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-build-swift %s -o %t/a.out4 -swift-version 4 && %target-run %t/a.out4
+// RUN: %target-build-swift %s -o %t/a.out4 -swift-version 4 && %target-codesign %t/a.out4 && %target-run %t/a.out4
 // REQUIRES: objc_interop
 // UNSUPPORTED: OS=watchos