GRExprEngine:
- Conjure symbols at '--' and '++' unary operations
- Add utility method SVal::GetConjuredSymbolVal() and constify some arguments
  along the way.

llvm-svn: 67395
diff --git a/clang/lib/Analysis/SymbolManager.cpp b/clang/lib/Analysis/SymbolManager.cpp
index 589178f..4d101f1 100644
--- a/clang/lib/Analysis/SymbolManager.cpp
+++ b/clang/lib/Analysis/SymbolManager.cpp
@@ -52,7 +52,8 @@
   return SymbolCounter++;
 }
 
-SymbolRef SymbolManager::getConjuredSymbol(Stmt* E, QualType T, unsigned Count,
+SymbolRef SymbolManager::getConjuredSymbol(const Stmt* E, QualType T,
+                                           unsigned Count,
                                            const void* SymbolTag) {
   
   llvm::FoldingSetNodeID profile;