Get codebase completely working with LLVM

You can now build Cosmopolitan with Clang:

    make -j8 MODE=llvm
    o/llvm/examples/hello.com

The assembler and linker code is now friendly to LLVM too.
So it's not needed to configure Clang to use binutils under
the hood. If you love LLVM then you can now use pure LLVM.

libc/alg/arraylist.internal.h

@@ -4,27 +4,8 @@
 #include "libc/mem/mem.h"
 #include "libc/str/str.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
-#if 0
-/**
- * @fileoverview Cosmopolitan Array List.
- *
- * This is a generically-typed ArrayList<T> template which follows a
- * duck-typing philosophy like Python, exporting an interface paradigm
- * similar to Go, that's implicitly defined by way of macros like Lisp.
- *
- *     struct MyArrayList {
- *       size_t i;  // current item count
- *       size_t n;  // current item capacity
- *       T *p;      // pointer to array (initially NULL)
- *     };
- *
- * Any struct with those fields can be used. It's also very important
- * that other data structures, which reference items in an arraylist, do
- * so using indices rather than pointers, since realloc() can relocate.
- *     
- * @see libc/mem/grow.c
- */
-#endif
+
+/* TOOD(jart): DELETE */
 
 #define append(ARRAYLIST, ITEM) concat((ARRAYLIST), (ITEM), 1)
 
@@ -38,7 +19,7 @@
     size_t Idx = List->i;                                                   \
     if (Idx + Count < List->n || __grow(&List->p, &List->n, SizE, Count)) { \
       memcpy(&List->p[Idx], Item, SizE *Count);                             \
-      atomic_store(&List->i, Idx + Count);                                  \
+      List->i = Idx + Count;                                                \
     } else {                                                                \
       Idx = -1UL;                                                           \
     }                                                                       \