internal/build:compile with c mode,when c file

runtime/internal/clite/ffi/_wrap/libffi.c

@@ -1,9 +1,5 @@
 #include <ffi.h>
 
-extern "C" {
-
 void *llog_ffi_closure_alloc(void **code) {
     return ffi_closure_alloc(sizeof(ffi_closure), code);
 }
-
-}

runtime/internal/clite/ffi/ffi_other.go

@@ -10,7 +10,7 @@ import (
 
 const (
 	LLGoPackage = "link: $(pkg-config --libs libffi); -lffi"
-	LLGoFiles   = "$(pkg-config --cflags libffi): _wrap/libffi.cpp"
+	LLGoFiles   = "$(pkg-config --cflags libffi): _wrap/libffi.c"
 )
 
 /*