Merge pull request #9304 from ruby/lock-diff-lcs

Lock diff-lcs < 2.0

(cherry picked from commit 89f7a86)

Author: hsbt

bundler/spec/spec_helper.rb

@@ -21,7 +21,7 @@
 
 # If we use shared GEM_HOME and install multiple versions, it may cause
 # unexpected test failures.
-gem "diff-lcs"
+gem "diff-lcs", "< 2.0"
 
 require "rspec/core"
 require "rspec/expectations"