[lldb] Bump macOS versions to 11 on the TestPlaygrounds test

This is necessary since macOS 11 was the first version to support ARM64,
and the compiler will silently bump up the triple when something < 11 is
specified.

Author: augusto2112

lldb/test/API/lang/swift/playgrounds/Contents.swift

@@ -17,7 +17,7 @@ let b = 5
 
 a + b
 
-@available(macOS 10.11, iOS 8.0, tvOS 8.0, watchOS 6.0, *) func newAPI() -> Int {
+@available(macOS 11.1, iOS 8.0, tvOS 8.0, watchOS 6.0, *) func newAPI() -> Int {
   return 11
 }
 

lldb/test/API/lang/swift/playgrounds/TestPlaygrounds.py

@@ -53,7 +53,7 @@ def get_build_triple(self):
                 version = '7.0'
             triple = '{}-{}-{}{}'.format(arch, vendor, os, version)
         else:
-            triple = '{}-apple-macosx10.10'.format(platform.machine())
+            triple = '{}-apple-macosx11.0'.format(platform.machine())
         return triple
 
     def get_run_triple(self):