Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibC/crt0.cpp

@@ -0,0 +1,54 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+extern "C" {
+
+int main(int, char**);
+
+int errno;
+char** environ;
+bool __environ_is_malloced;
+
+void __libc_init()
+{
+    void __malloc_init();
+    __malloc_init();
+
+    void __stdio_init();
+    __stdio_init();
+}
+
+int _start(int argc, char** argv, char** env)
+{
+    environ = env;
+    __environ_is_malloced = false;
+
+    __libc_init();
+
+    extern void _init();
+    _init();
+
+    extern void (*__init_array_start[])(int, char**, char**) __attribute__((visibility("hidden")));
+    extern void (*__init_array_end[])(int, char**, char**) __attribute__((visibility("hidden")));
+
+    const size_t size = __init_array_end - __init_array_start;
+    for (size_t i = 0; i < size; i++)
+        (*__init_array_start[i])(argc, argv, env);
+
+    int status = main(argc, argv);
+
+    exit(status);
+
+    return 20150614;
+}
+
+[[noreturn]] void __cxa_pure_virtual()
+{
+    ASSERT_NOT_REACHED();
+}
+
+void __cxa_atexit()
+{
+}
+}