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/mem/realloc_in_place.S

@@ -20,19 +20,19 @@
 #include "libc/notice.inc"
 .source	__FILE__
 
-/	Resizes the space allocated for p to size n, only if this can be
-/	done without moving p (i.e., only if there is adjacent space
-/	available if n is greater than p's current allocated size, or n
-/	is less than or equal to p's size). This may be used instead of
-/	plain realloc if an alternative allocation strategy is needed
-/	upon failure to expand space, for example, reallocation of a
-/	buffer that must be memory-aligned or cleared. You can use
-/	realloc_in_place to trigger these alternatives only when needed.
-/
-/	@param	rdi (p) is address of current allocation
-/	@param	rsi (newsize) is number of bytes needed
-/	@return	rax is result, or NULL w/ errno
-/	@see	dlrealloc_in_place()
+//	Resizes the space allocated for p to size n, only if this can be
+//	done without moving p (i.e., only if there is adjacent space
+//	available if n is greater than p's current allocated size, or n
+//	is less than or equal to p's size). This may be used instead of
+//	plain realloc if an alternative allocation strategy is needed
+//	upon failure to expand space, for example, reallocation of a
+//	buffer that must be memory-aligned or cleared. You can use
+//	realloc_in_place to trigger these alternatives only when needed.
+//
+//	@param	rdi (p) is address of current allocation
+//	@param	rsi (newsize) is number of bytes needed
+//	@return	rax is result, or NULL w/ errno
+//	@see	dlrealloc_in_place()
 realloc_in_place:
 	jmp	*hook_realloc_in_place(%rip)
 	.endfn	realloc_in_place,globl