Added entrypoint of acospif16 to file after syncing with upstream main

Author: amemov

libc/config/linux/x86_64/entrypoints.txt

@@ -657,6 +657,7 @@ if(LIBC_TYPES_HAS_FLOAT16)
   list(APPEND TARGET_LIBM_ENTRYPOINTS
     # math.h C23 _Float16 entrypoints
     libc.src.math.acosf16
+    libc.src.math.acospif16
     libc.src.math.acoshf16
     libc.src.math.asinf16
     libc.src.math.asinhf16