[libc] fix up the use of angle includes in include/ (#86027)

Performed en-masse via:

    $ grep -rn "#include <ll" libc/include -l | \
      xargs perl -pi -e 's/#include <ll(.*)>/#include "ll$1"/'
    $ grep -rn "#include <__" libc/include -l | \
      xargs perl -pi -e 's/#include <__(.*)>/#include "__$1"/'

Link: #83463
Link: #83210
diff --git a/libc/include/sys/wait.h.def b/libc/include/sys/wait.h.def
index b4fcce4..0a76da0 100644
--- a/libc/include/sys/wait.h.def
+++ b/libc/include/sys/wait.h.def
@@ -9,9 +9,9 @@
 #ifndef LLVM_LIBC_SYS_WAIT_H
 #define LLVM_LIBC_SYS_WAIT_H
 
-#include <__llvm-libc-common.h>
+#include "__llvm-libc-common.h"
 
-#include <llvm-libc-macros/sys-wait-macros.h>
+#include "llvm-libc-macros/sys-wait-macros.h"
 
 %%public_api()