Kernel/Userspace/LibC: Implement basic dprintln for userspace

libc/include/stdio.h

@@ -53,6 +53,8 @@ extern FILE* __stdout;
 #define stdout __stdout
 extern FILE* __stderr;
 #define stderr __stderr
+extern FILE* __stddbg;
+#define stddbg __stddbg
 
 void	clearerr(FILE* stream);
 char*	ctermid(char* s);

libc/include/unistd.h

@@ -120,6 +120,7 @@ __BEGIN_DECLS
 #define STDIN_FILENO 0
 #define STDOUT_FILENO 1
 #define STDERR_FILENO 2
+#define STDDBG_FILENO 3
 
 #define _POSIX_VDISABLE 0
 

libc/stdio.cpp

@@ -22,11 +22,13 @@ static FILE s_files[FOPEN_MAX] {
 	{ .fd = STDIN_FILENO  },
 	{ .fd = STDOUT_FILENO },
 	{ .fd = STDERR_FILENO },
+	{ .fd = STDDBG_FILENO },
 };
 
 FILE* stdin  = &s_files[0];
 FILE* stdout = &s_files[1];
 FILE* stderr = &s_files[2];
+FILE* stddbg = &s_files[3];
 
 void clearerr(FILE* file)
 {