[lldb] Readd deleted variable in the sample test

In D102771 wanted to make `test_var` global to demonstrate the a no-launch test,
but the old variable is still needed for another test. This just creates the
global var with a different name to demonstrate the no-launch functionality.

lldb/test/API/sample_test/TestSampleTest.py

@@ -50,4 +50,4 @@ class RenameThisSampleTestTestCase(TestBase):
         """ Same as above but doesn't launch a process."""
 
         target = self.createTestTarget()
-        self.expect_expr("test_var", result_value="10")
+        self.expect_expr("global_test_var", result_value="10")

lldb/test/API/sample_test/main.c

@@ -1,14 +1,15 @@
 #include <stdio.h>
 
-int test_var = 10;
+int global_test_var = 10;
 
 int
 main()
 {
+  int test_var = 10;
   printf ("Set a breakpoint here: %d.\n", test_var);
   //% test_var = self.frame().FindVariable("test_var")
   //% test_value = test_var.GetValueAsUnsigned()
   //% self.assertTrue(test_var.GetError().Success(), "Failed to fetch test_var")
   //% self.assertEqual(test_value, 10, "Failed to get the right value for test_var")
-  return 0;
+  return global_test_var;
 }