Fix version bugs

Swift 5.3 was the Swift stdlib from 11.0 up to and including 11.2, not
11.3.

Swift 5.3 was active from watchOS 7.0 up to and including 7.3, not 7.4.

Author: etcwilde

lib/Basic/Platform.cpp

@@ -426,7 +426,7 @@ swift::getSwiftRuntimeCompatibilityVersionForTarget(
         }
       }
     } else if (Major == 11) {
-      if (Minor <= 3)
+      if (Minor <= 2)
         return floorFor64(llvm::VersionTuple(5, 3));
 
       return floorFor64(llvm::VersionTuple(5, 4));
@@ -489,7 +489,7 @@ swift::getSwiftRuntimeCompatibilityVersionForTarget(
         return floorFor64bits(llvm::VersionTuple(5, 2));
       }
     } else if (Major <= 7) {
-      if (Minor <= 4)
+      if (Minor <= 3)
         return floorFor64bits(llvm::VersionTuple(5, 3));
 
       return floorFor64bits(llvm::VersionTuple(5, 4));