[Bug target/78478] Compile Error for i386-rtems

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78478

--- Comment #13 from H.J. Lu <hjl.tools at gmail dot com> ---
The problem is config/i386/rtemself.h has

#define LONG_DOUBLE_TYPE_SIZE (TARGET_80387 ? 80 : 64)

XFmode isn't available with -msoft-float even when -mlong-double-80 is used.
IA MCU defaults long double to double and XFmode is available with
-mlong-double-80.