<sys/stat.h>: add lchmod().

Bug: http://b/361334945
Change-Id: I6a76db7bd2f657ad9b058c2672bf7a4e687017f9
diff --git a/libc/Android.bp b/libc/Android.bp
index 107db88..a81999d 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -913,6 +913,7 @@
         "bionic/isatty.cpp",
         "bionic/killpg.cpp",
         "bionic/langinfo.cpp",
+        "bionic/lchmod.cpp",
         "bionic/lchown.cpp",
         "bionic/lfs64_support.cpp",
         "bionic/libc_init_common.cpp",