[Polly] Move SimplifyVisitor into polly namespace.

Declarations in headers should not be in the anonymous
namespace. Compilers also warn about the use of
<anon namespace>::SimplifyVisitor as a public field in
polly::SimplifyPass and polly::SimplifyPrinterPass.

polly/include/polly/Simplify.h

@@ -22,7 +22,7 @@ class PassRegistry;
 class Pass;
 } // namespace llvm
 
-namespace {
+namespace polly {
 class SimplifyVisitor {
 private:
   /// The invocation id (if there are multiple instances in the pass manager's
@@ -114,7 +114,7 @@ class SimplifyVisitor {
 
   void releaseMemory();
 };
-} // namespace
+} // namespace polly
 
 namespace polly {
 

polly/lib/Transform/Simplify.cpp

@@ -116,6 +116,7 @@ static isl::union_map underapproximatedAddMap(isl::union_map UMap,
 
   return UResult;
 }
+} // namespace
 
 /// Return whether at least one simplification has been applied.
 bool SimplifyVisitor::isModified() const {
@@ -678,6 +679,7 @@ void SimplifyVisitor::releaseMemory() {
   StmtsRemoved = 0;
 }
 
+namespace {
 class SimplifyLegacyPass : public ScopPass {
 public:
   static char ID;