sim, sim/{m32c,ppc,rl78}: Use getopt_long

Because of a Libiberty hack, getopt on GNU libc (2.25 or earlier) is
currently unusable on sim, causing a regression on CentOS 7.

This is caused as follows:

1.  If HAVE_DECL_GETOPT is defined (getopt declaration with known prototype
    is detected while configuration), a declaration of getopt in
    "include/getopt.h" is suppressed.
    The author started to define HAVE_DECL_GETOPT in sim with the commit
    340aa4f6872c ("sim: Check known getopt definition existence").
2.  GNU libc (2.25 or earlier)'s <unistd.h> includes <getopt.h> with a
    special purpose macro defined to declare only getopt function but due
    to include path (not tested while configuration), it causes <unistd.h>
    to include Libiberty's "include/getopt.h".
3.  If both 1. and 2. are satisfied, despite that <unistd.h> tries to
    declare getopt by including <getopt.h>, "include/getopt.h" does not do
    so, causing getopt function undeclared.

Getting rid of "include/getopt.h" (e.g. renaming this header file) is the
best solution to avoid hacking but as a short-term solution, this commit
replaces getopt with getopt_long under sim/.

1 files changed, 6 insertions, 3 deletions

diff --git a/sim/ppc/igen.c b/sim/ppc/igen.c
index 27b4863..445afb9 100644
--- a/sim/ppc/igen.c
+++ b/sim/ppc/igen.c
@@ -351,6 +351,7 @@ main(int argc,
   filter *filters = NULL;
   insn_table *instructions = NULL;
   table_include *includes = NULL;
+  static const struct option longopts[] = { { 0 } };
   char *real_file_name = NULL;
   int is_header = 0;
   int ch;
@@ -390,9 +391,11 @@ main(int argc,
     printf("  -f <output-file>      output support functions\n");
   }
 
-  while ((ch = getopt(argc, argv,
-		      "F:EI:RSLJT:CB:H:N:o:k:i:n:hc:d:m:s:t:f:"))
-	 != -1) {
+  while (
+      (ch = getopt_long (argc, argv, "F:EI:RSLJT:CB:H:N:o:k:i:n:hc:d:m:s:t:f:",
+			 longopts, NULL))
+      != -1)
+  {
 #if 0  /* For debugging.  */
     fprintf(stderr, "\t-%c %s\n", ch, (optarg ? optarg : ""));
 #endif