Fix #361 - Initialize clspv passes into the registry. (#369)

* Fix #361 - Initialize clspv passes into the registry.

Passes were not registering their print-after/print-before flags.  This
calls the pass initializer and adds a test for a clspv pass.
diff --git a/lib/Compiler.cpp b/lib/Compiler.cpp
index 5fb153f..b71d030 100644
--- a/lib/Compiler.cpp
+++ b/lib/Compiler.cpp
@@ -809,6 +809,7 @@
   llvm::PassRegistry &Registry = *llvm::PassRegistry::getPassRegistry();
   llvm::initializeCore(Registry);
   llvm::initializeScalarOpts(Registry);
+  llvm::initializeClspvPasses(Registry);
 
   std::unique_ptr<llvm::Module> module(action.takeModule());
 
@@ -934,6 +935,7 @@
   llvm::PassRegistry &Registry = *llvm::PassRegistry::getPassRegistry();
   llvm::initializeCore(Registry);
   llvm::initializeScalarOpts(Registry);
+  llvm::initializeClspvPasses(Registry);
 
   std::unique_ptr<llvm::Module> module(action.takeModule());