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

Author: swift-ci

lib/Sema/TypeCheckExpr.cpp

@@ -416,7 +416,7 @@ namespace {
       if (!group) return false;
       if (storedGroup == group) return !GroupAndIsStrict.getInt();
       return TC.Context.associateInfixOperators(group, storedGroup)
-               == Associativity::Left;
+               != Associativity::Right;
     }
   };
 } // end anonymous namespace

test/Constraints/operator.swift

@@ -237,3 +237,21 @@ func sr10843() {
   (^^^)(s, s)
   _ = (==)(0, 0)
 }
+
+// SR-10970
+precedencegroup PowerPrecedence {
+  lowerThan: BitwiseShiftPrecedence
+  higherThan: AdditionPrecedence
+  associativity: right
+}
+infix operator ^^ : PowerPrecedence
+
+extension Int {
+  static func ^^ (lhs: Int, rhs: Int) -> Int {
+    var result = 1
+    for _ in 1...rhs { result *= lhs }
+    return result
+  }
+}
+
+_ = 1 ^^ 2 ^^ 3 * 4 // expected-error {{adjacent operators are in unordered precedence groups 'PowerPrecedence' and 'MultiplicationPrecedence'}}