PR fortran/31645

	* scanner.c (load_file): Discard the byte order mark if one is
	found on the first non-preprocessor line of a file.

	* testsuite/gfortran.dg/bom_error.f90: New test.
	* testsuite/gfortran.dg/bom_include.f90: New test.
	* testsuite/gfortran.dg/bom_UTF16-LE.f90: New test.
	* testsuite/gfortran.dg/bom_UTF16-BE.f90: New test.
	* testsuite/gfortran.dg/bom_UTF-8.f90: New test.
	* testsuite/gfortran.dg/bom_UTF-32.f90: New test.
	* testsuite/gfortran.dg/bom_UTF-8.F90: New test.
	* testsuite/gfortran.dg/bom_include.inc: New file.

From-SVN: r124274