merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/blob.h

@@ -0,0 +1,25 @@
+#ifndef BLOB_H
+#define BLOB_H
+
+#include "object.h"
+
+extern const char *blob_type;
+
+struct blob {
+	struct object object;
+};
+
+struct blob *lookup_blob(struct repository *r, const struct object_id *oid);
+
+int parse_blob_buffer(struct blob *item, void *buffer, unsigned long size);
+
+/**
+ * Blobs do not contain references to other objects and do not have
+ * structured data that needs parsing. However, code may use the
+ * "parsed" bit in the struct object for a blob to determine whether
+ * its content has been found to actually be available, so
+ * parse_blob_buffer() is used (by object.c) to flag that the object
+ * has been read successfully from the database.
+ **/
+
+#endif /* BLOB_H */