Support %mc/%ms/%m[ in sscanf.

Also support the "long" (wchar_t) variants.

Bug: http://b/68672236
Test: ran tests
Change-Id: I060e98b4d2feb61e12986d9d51e4710b2b1d9724
diff --git a/libc/Android.bp b/libc/Android.bp
index 3ff5c03..bd6b574 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -18,7 +18,7 @@
     "stdio/refill.c",
     "stdio/stdio.cpp",
     "stdio/stdio_ext.cpp",
-    "stdio/vfscanf.c",
+    "stdio/vfscanf.cpp",
     "stdio/vfwscanf.c",
     "stdlib/exit.c",
 ]