semihosting: Create qemu_semihosting_guestfd_init

For arm-compat, initialize console_{in,out}_gf;
otherwise, initialize stdio file descriptors.

This will go some way to cleaning up arm-compat, and
will allow other semihosting to use normal stdio.

Reviewed-by: Luc Michel <lmichel@kalray.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/main.c

@@ -54,6 +54,10 @@
 #include "loader.h"
 #include "user-mmap.h"
 
+#ifdef CONFIG_SEMIHOSTING
+#include "semihosting/semihost.h"
+#endif
+
 #ifndef AT_FLAGS_PRESERVE_ARGV0
 #define AT_FLAGS_PRESERVE_ARGV0_BIT 0
 #define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
@@ -906,6 +910,11 @@ int main(int argc, char **argv, char **envp)
         }
         gdb_handlesig(cpu, 0);
     }
+
+#ifdef CONFIG_SEMIHOSTING
+    qemu_semihosting_guestfd_init();
+#endif
+
     cpu_loop(env);
     /* never exits */
     return 0;