Fix build with LLVM 3.1 ToT

Makefile

@@ -13,7 +13,7 @@ ARCH_TYPE = $(shell arch)
 ifeq ($(shell llvm-config --version), 3.1svn)
   LLVM_LIBS=-lLLVMAsmParser -lLLVMInstrumentation -lLLVMLinker			\
 	-lLLVMArchive -lLLVMBitReader -lLLVMDebugInfo -lLLVMJIT -lLLVMipo	\
-	-lLLVMBitWriter -lLLVMTableGen -lLLVMCBackendInfo			\
+	-lLLVMBitWriter -lLLVMTableGen 			\
 	-lLLVMX86Disassembler -lLLVMX86CodeGen -lLLVMSelectionDAG		\
 	-lLLVMAsmPrinter -lLLVMX86AsmParser -lLLVMX86Desc -lLLVMX86Info		\
 	-lLLVMX86AsmPrinter -lLLVMX86Utils -lLLVMMCDisassembler	-lLLVMMCParser	\

cbackend.cpp

@@ -933,6 +933,20 @@ void CWriter::printConstantDataSequential(ConstantDataSequential *CDS,
 }
 #endif // LLVM_3_1svn
 
+#ifdef LLVM_3_1svn
+static inline std::string ftostr(const APFloat& V) {
+  std::string Buf;
+  if (&V.getSemantics() == &APFloat::IEEEdouble) {
+    raw_string_ostream(Buf) << V.convertToDouble();
+    return Buf;
+  } else if (&V.getSemantics() == &APFloat::IEEEsingle) {
+    raw_string_ostream(Buf) << (double)V.convertToFloat();
+    return Buf;
+  }
+  return "<unknown format in ftostr>"; // error
+}
+#endif // LLVM_3_1svn
+
 // isFPCSafeToPrint - Returns true if we may assume that CFP may be written out
 // textually as a double (rather than as a reference to a stack-allocated
 // variable). We decide this by converting CFP to a string and back into a