cmake: Add option POLLY_USE_CLOOG This allows to build Polly without CLooG. git-svn-id: https://llvm.org/svn/llvm-project/polly/branches/release_34@195348 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3bddfa4..1b63b6b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt

@@ -81,9 +81,14 @@
 
 FIND_PACKAGE(Isl REQUIRED)
 FIND_PACKAGE(Gmp REQUIRED)
-FIND_PACKAGE(Cloog)
 FIND_PACKAGE(Pluto)
 
+option(POLLY_USE_CLOOG "Build Polly with Cloog support" ON)
+if (POLLY_USE_CLOOG)
+  # Build Cloog support in Polly (default is for cloog-isl).
+  FIND_PACKAGE(Cloog)
+endif(POLLY_USE_CLOOG)
+
 option(POLLY_ENABLE_GPGPU_CODEGEN "Enable GPGPU code generation feature" OFF)
 if (POLLY_ENABLE_GPGPU_CODEGEN)
   # Do not require CUDA, as GPU code generation test cases can be run without