provide loff_t as typedef

muslc defines those, but we want a typedef instead

solution copied from libgo
https://gcc.gnu.org/pipermail/gcc-patches/2022-April/593527.html

Author: GitMensch

src/EmuFs.cc

@@ -10,6 +10,13 @@
 #include <sstream>
 #include <string>
 
+// muslc defines those, but we want a typedef instead
+#if defined(loff_t)
+typedef loff_t __musl_loff_t;
+#undef loff_t
+typedef __musl_loff_t loff_t;
+#endif
+
 #include "AddressSpace.h"
 #include "ReplaySession.h"
 #include "core.h"

src/ScopedFd.h

@@ -3,6 +3,9 @@
 #ifndef RR_SCOPED_FD_H_
 #define RR_SCOPED_FD_H_
 
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/types.h>

src/record_syscall.cc

@@ -102,6 +102,13 @@
 #include "log.h"
 #include "util.h"
 
+// muslc defines those, but we want a typedef instead
+#if defined(loff_t)
+typedef loff_t __musl_loff_t;
+#undef loff_t
+typedef __musl_loff_t loff_t;
+#endif
+
 using namespace std;
 
 #ifndef HAVE_TERMIOS2