Added Delta IR Reduction Tool

Summary: Tool parses input IR file, and runs the delta debugging algorithm to reduce the functions inside the input file.

Reviewers: alexshap, chandlerc

Subscribers: mgorny, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63672

> llvm-svn: 368071

llvm-svn: 368358
diff --git a/llvm/test/Reduce/Inputs/remove-funcs.py b/llvm/test/Reduce/Inputs/remove-funcs.py
new file mode 100755
index 0000000..dc0203c
--- /dev/null
+++ b/llvm/test/Reduce/Inputs/remove-funcs.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+
+import sys
+
+input = open(sys.argv[1], "r")
+for line in input:
+  if "@interesting" in line:
+    sys.exit(0)
+
+sys.exit(1) # IR isn't interesting