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/Assembler/upgrade-loop-metadata.ll b/llvm/test/Assembler/upgrade-loop-metadata.ll
index 05bd2ad..c05e1a2 100644
--- a/llvm/test/Assembler/upgrade-loop-metadata.ll
+++ b/llvm/test/Assembler/upgrade-loop-metadata.ll
@@ -5,7 +5,7 @@
 ;
 ; RUN: llvm-as < %s | llvm-dis | FileCheck %s
 ; RUN: opt -S < %s | FileCheck %s
-; RUN: verify-uselistorder %s -preserve-bc-use-list-order -num-shuffles=5
+; RUN: verify-uselistorder %s -preserve-bc-use-list-order
 
 define void @_Z28loop_with_vectorize_metadatav() {
 entry: