Introduce llvm-c function LLVMPrintModuleToFile.

This lets you save the textual representation of the LLVM IR to a file.
Before this patch it could only be printed to STDERR from llvm-c.

Patch by Carlo Kok!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156479 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm-c/Core.h

@@ -477,6 +477,15 @@ void LLVMSetTarget(LLVMModuleRef M, const char *Triple);
  */
 void LLVMDumpModule(LLVMModuleRef M);
 
+/**
+ * Print a representation of a module to a file. The ErrorMessage needs to be
+ * disposed with LLVMDisposeMessage. Returns 0 on success, 1 otherwise.
+ *
+ * @see Module::print()
+ */
+LLVMBool LLVMPrintModuleToFile(LLVMModuleRef M, const char *Filename,
+                               char **ErrorMessage);
+
 /**
  * Set inline assembly for a module.
  *