verify-uselistorder: Change the default -num-shuffles=5

Change the default for `-num-shuffles` to 5 and better document the
algorithm in the header docs of `verify-uselistorder`.

llvm-svn: 214419
diff --git a/llvm/test/Bitcode/visibility-styles.3.2.ll b/llvm/test/Bitcode/visibility-styles.3.2.ll
index aecbc65..00672cb 100644
--- a/llvm/test/Bitcode/visibility-styles.3.2.ll
+++ b/llvm/test/Bitcode/visibility-styles.3.2.ll
@@ -1,5 +1,5 @@
 ; RUN:  llvm-dis < %s.bc| FileCheck %s
-; RUN:  verify-uselistorder < %s.bc -preserve-bc-use-list-order -num-shuffles=5
+; RUN:  verify-uselistorder < %s.bc -preserve-bc-use-list-order
 
 ; visibility-styles.3.2.ll.bc was generated by passing this file to llvm-as-3.2.
 ; The test checks that LLVM does not silently misread visibility styles of