Apply changes to migrate to llvm upstream r135568.

- Remove the const qualifier of llvm::Type and
  llvm::PointerType due to the API change.

- Update the relocation model setup code, since
  llvm::TargetMachine changes the API.

- Qualify dyn_cast with llvm namespace.

Change-Id: I4820fb86effc3a62569e19a6a8753ba9e960f6b2
diff --git a/slang_rs_backend.cpp b/slang_rs_backend.cpp
index 2d05ff0..f07be08 100644
--- a/slang_rs_backend.cpp
+++ b/slang_rs_backend.cpp
@@ -84,7 +84,7 @@
     // Iterate all function declarations in the program.
     for (clang::DeclGroupRef::iterator I = D.begin(), E = D.end();
          I != E; I++) {
-      clang::FunctionDecl *FD = dyn_cast<clang::FunctionDecl>(*I);
+      clang::FunctionDecl *FD = llvm::dyn_cast<clang::FunctionDecl>(*I);
       if (FD == NULL)
         continue;
       if (!FD->getName().startswith("rs"))  // Check prefix
@@ -100,7 +100,7 @@
 
   // Process any non-static function declarations
   for (clang::DeclGroupRef::iterator I = D.begin(), E = D.end(); I != E; I++) {
-    clang::FunctionDecl *FD = dyn_cast<clang::FunctionDecl>(*I);
+    clang::FunctionDecl *FD = llvm::dyn_cast<clang::FunctionDecl>(*I);
     if (FD && FD->isGlobal()) {
       AnnotateFunction(FD);
     }
@@ -139,7 +139,7 @@
           DE = TUDecl->decls_end();
        DI != DE;
        DI++) {
-    clang::VarDecl *VD = dyn_cast<clang::VarDecl>(*DI);
+    clang::VarDecl *VD = llvm::dyn_cast<clang::VarDecl>(*DI);
     if (VD && !ValidateVarDecl(VD)) {
       valid = false;
     }
@@ -172,7 +172,7 @@
           E = TUDecl->decls_end(); I != E; I++) {
     if ((I->getKind() >= clang::Decl::firstFunction) &&
         (I->getKind() <= clang::Decl::lastFunction)) {
-      clang::FunctionDecl *FD = dyn_cast<clang::FunctionDecl>(*I);
+      clang::FunctionDecl *FD = llvm::dyn_cast<clang::FunctionDecl>(*I);
       if (FD && !FD->isGlobal()) {
         AnnotateFunction(FD);
       }