Allow a second -T<section>=<addr> to override a previous version on the same linker command line.

PR ld/20302
	* lexsup.c (set_segment_start): If resetting the start address of
	a section, remember to generate a new script element as well.
	* testsuite/ld-scripts/pr20302.d: New test.
	* testsuite/ld-scripts/scripts.exp: Run the new test.

ld/lexsup.c

@@ -1686,6 +1686,7 @@ set_segment_start (const char *section, char *valstr)
     if (strcmp (seg->name, name) == 0)
       {
 	seg->value = val;
+	lang_section_start (section, exp_intop (val), seg);
 	return;
       }
   /* There was no existing value so we must create a new segment