ldso: add memcpy and memset to symbol.map

On ARM, the compiler generates calls to memcpy and memset. Most
dynamically linked programs use the libc, which provides these
functions. However, if a dynamically linked program does not use the
libc (e.g., noux/minimal or the new version of cli_monitor), those
symbols remain unresolved. By adding them to ldso's symbol.map, the
dynamic linker will resolve them with the functions of the cxx
library, which is part of the dynamic linker.

Issue #1561

repos/base/src/lib/ldso/symbol.map

@@ -23,6 +23,13 @@
 		};
 		__dynamic_cast;
 
+		/*
+		 * Symbols for calls generated by the compiler (i.e., on ARM), and
+		 * provided by the C++ runtime.
+		 */
+		 memcpy;
+		 memset;
+
 		/*
 		 * Debugging
 		 */