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.

dsp/tty/mpsadbw.S

@@ -18,7 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/macros.h"
 
-/	TODO(jart): write me
+//	TODO(jart): write me
 
 	movdqa	a,%xmm0
 	mpsadbw $0,inv,%xmm0

dsp/tty/windex-avx2.S

@@ -19,11 +19,11 @@
 #include "libc/macros.h"
 .source	__FILE__
 
-/	Returns index of minimum uint16 in array.
-/
-/	@param	rdi points to nonempty array
-/	@param	rsi is item count divisible by 16
-/	@note	needs avx2 (haswell+)
+//	Returns index of minimum uint16 in array.
+//
+//	@param	rdi points to nonempty array
+//	@param	rsi is item count divisible by 16
+//	@note	needs avx2 (haswell+)
 windex_avx2:
 	push	%rbp
 	mov	%rsp,%rbp

dsp/tty/windex-sse4.S

@@ -19,11 +19,11 @@
 #include "libc/macros.h"
 .source	__FILE__
 
-/	Returns index of minimum positive int16 in array.
-/
-/	@param	rdi points to nonempty array
-/	@param	esi is 16-byte aligned 8+ / 8 multiple array item count
-/	@note	needs sse4 (nehalem+)
+//	Returns index of minimum positive int16 in array.
+//
+//	@param	rdi points to nonempty array
+//	@param	esi is 16-byte aligned 8+ / 8 multiple array item count
+//	@note	needs sse4 (nehalem+)
 windex_sse4:
 	push	%rbp
 	mov	%rsp,%rbp

dsp/tty/windex.S

@@ -20,7 +20,7 @@
 #include "libc/macros.h"
 .source	__FILE__
 
-/	Dispatches to fastest windex() implementation.
+//	Dispatches to fastest windex() implementation.
 	.initbss 300,_init_windex
 windex:	.quad	0
 	.endobj	windex,globl