LTO API: add lto_module_create_from_memory_with_path.

This function adds an extra path argument to lto_module_create_from_memory.
The path argument will be passed to makeBuffer to make sure the MemoryBuffer
has a name and the created module has a module identifier.

This is mainly for emitting warning messages from the linker. When we emit
warning message on a module, we can use the module identifier.

rdar://15985737

llvm-svn: 201114
diff --git a/llvm/include/llvm-c/lto.h b/llvm/include/llvm-c/lto.h
index fbad2b5..bff63ad 100644
--- a/llvm/include/llvm-c/lto.h
+++ b/llvm/include/llvm-c/lto.h
@@ -40,7 +40,7 @@
  * @{
  */
 
-#define LTO_API_VERSION 8
+#define LTO_API_VERSION 9
 
 /**
  * \since prior to LTO_API_VERSION=3
@@ -176,6 +176,16 @@
 lto_module_create_from_memory(const void* mem, size_t length);
 
 /**
+ * Loads an object file from memory with an extra path argument.
+ * Returns NULL on error (check lto_get_error_message() for details).
+ *
+ * \since prior to LTO_API_VERSION=9
+ */
+extern lto_module_t
+lto_module_create_from_memory_with_path(const void* mem, size_t length,
+                                        const char *path);
+
+/**
  * Loads an object file from disk. The seek point of fd is not preserved.
  * Returns NULL on error (check lto_get_error_message() for details).
  *