StdlibUnittest: add an argument label to checkHashable

I think it improves readability of the callsite.

Author: gribozavr

stdlib/private/StdlibUnittest/StdlibUnittest.swift.gyb

@@ -2073,7 +2073,7 @@ public func checkHashable<Instances : Collection>(
 }
 
 public func checkHashable<T : Hashable>(
-  _ expectedEqual: Bool, _ lhs: T, _ rhs: T, ${TRACE}
+  expectedEqual: Bool, _ lhs: T, _ rhs: T, ${TRACE}
 ) {
   checkHashable(
     [lhs, rhs], equalityOracle: { expectedEqual || $0 == $1 }, ${trace})

test/stdlib/FloatingPoint.swift.gyb

@@ -518,7 +518,9 @@ func checkFloatingPointComparison_${FloatSelf}(
   let message = { "expected: lhs=\(lhs) \(expected) rhs=\(rhs)" }
   expectEqual(expected.isEQ(), lhs == rhs, message(), stackTrace: newTrace)
   expectEqual(expected.isNE(), lhs != rhs, message(), stackTrace: newTrace)
-  checkHashable(expected.isEQ(), lhs, rhs, message(), stackTrace: newTrace)
+  checkHashable(
+    expectedEqual: expected.isEQ(),
+    lhs, rhs, message(), stackTrace: newTrace)
 
   expectEqual(expected.isLT(), lhs < rhs, message(), stackTrace: newTrace)
   expectEqual(expected.isLE(), lhs <= rhs, message(), stackTrace: newTrace)

test/stdlib/StringAPI.swift

@@ -145,7 +145,8 @@ func checkStringComparison(
   expectEqual(expected.isEQ(), lhs == rhs, stackTrace: stackTrace)
   expectEqual(expected.isNE(), lhs != rhs, stackTrace: stackTrace)
   checkHashable(
-    expected.isEQ(), lhs, rhs, stackTrace: stackTrace.withCurrentLoc())
+    expectedEqual: expected.isEQ(),
+    lhs, rhs, stackTrace: stackTrace.withCurrentLoc())
 
   expectEqual(expected.isLT(), lhs < rhs, stackTrace: stackTrace)
   expectEqual(expected.isLE(), lhs <= rhs, stackTrace: stackTrace)
@@ -167,7 +168,8 @@ func checkStringComparison(
     !expectedEqualUnicodeScalars, lhsNSString != rhsNSString,
     stackTrace: stackTrace)
   checkHashable(
-    expectedEqualUnicodeScalars, lhsNSString, rhsNSString,
+    expectedEqual: expectedEqualUnicodeScalars,
+    lhsNSString, rhsNSString,
     stackTrace: stackTrace.withCurrentLoc())
 #endif
 }
@@ -215,7 +217,8 @@ func checkCharacterComparison(
   expectEqual(expected.isEQ(), lhs == rhs, stackTrace: stackTrace)
   expectEqual(expected.isNE(), lhs != rhs, stackTrace: stackTrace)
   checkHashable(
-    expected.isEQ(), lhs, rhs, stackTrace: stackTrace.withCurrentLoc())
+    expectedEqual: expected.isEQ(),
+    lhs, rhs, stackTrace: stackTrace.withCurrentLoc())
 
   expectEqual(expected.isLT(), lhs < rhs, stackTrace: stackTrace)
   expectEqual(expected.isLE(), lhs <= rhs, stackTrace: stackTrace)