Add %b and %B support to the printf/wprintf family.

Coming to C23 via WG14 N2630, and already in glibc.

We're still missing clang support for %b and %B in format string checking,
but it's probably easier to fix this first. (Apparently GCC already has
support because of glibc.)

Test: treehugger
Change-Id: Ie8bfe4630d00c50e1d047d6756a7f799205356db
diff --git a/libc/stdio/printf_common.h b/libc/stdio/printf_common.h
index 4dc5ca1..e761835 100644
--- a/libc/stdio/printf_common.h
+++ b/libc/stdio/printf_common.h
@@ -524,6 +524,8 @@
       case 'u':
       case 'X':
       case 'x':
+      case 'B':
+      case 'b':
         ADDUARG();
         break;
       default: /* "%?" prints ?, unless ? is NUL */