Add changes for LLVM 3.2

- The Attributes class was changed again
- TargetData was renamed to DataLayout

Compiles again with LLVm 3.0, 3.1 and trunk(3.2).

gen/irstate.cpp

@@ -17,7 +17,11 @@
 
 IRState* gIR = 0;
 llvm::TargetMachine* gTargetMachine = 0;
-const llvm::TargetData* gTargetData = 0;
+#if LDC_LLVM_VER >= 302
+const llvm::DataLayout* gDataLayout = 0;
+#else
+const llvm::TargetData* gDataLayout = 0;
+#endif
 TargetABI* gABI = 0;
 
 //////////////////////////////////////////////////////////////////////////////////////////