added new memory allocator files and README

allocator/bump_alloc/bump_alloc.h

@@ -0,0 +1,18 @@
+/**********************************
+ * bump_alloc.h
+ * Jeremy.Singer@glasgow.ac.uk
+ *
+ * This is a simple bump-pointer allocator.
+ * It mmaps a large buffer of SIZE bytes,
+ * then allocates this space in word-sized
+ * chunks to client code (in main fn).
+ *
+ * Initial simple memory allocator test.
+ * Explore capability narrowing operations
+ * and intrinsics for bound reporting.
+ */
+
+void init_alloc(int size_in_bytes);
+
+char *bump_alloc(int bytes); /* the simplest malloc */
+                             /* oh, and there's no free() ! */