[test] Disable dropped-var.sil

rdar://141272451

Author: hamishknight

test/DebugInfo/dropped-var.sil

@@ -1,6 +1,8 @@
  // RUN: %target-sil-opt --diagnose-unreachable -o - %s -sil-stats-lost-variables --target=aarch64-apple-darwin 2>&1 | %FileCheck %s
  // REQUIRES:CPU=aarch64
 
+ // REQUIRES: rdar141272451
+
  // CHECK: function, lostvars, Pass List Pipeline, DiagnoseUnreachable, 1, 1, {{[0-9]+}}, $s4test3bar1yS2i_tF
 
 sil_stage raw