Fix portability breakage in pg_dump.

Commit 0eea8047 introduced some overly
optimistic assumptions about what could be in a local struct variable's
initializer.  (This might in fact be valid code according to C99, but I've
got at least one pre-C99 compiler that falls over on those nonconstant
address expressions.)  There is no reason whatsoever for main()'s workspace
to not be static, so revert long_options[] to a static and make the
DumpOptions struct static as well.

src/bin/pg_dump/pg_backup.h

@@ -269,6 +269,7 @@ extern void PrintTOCSummary(Archive *AH, RestoreOptions *ropt);
 extern RestoreOptions *NewRestoreOptions(void);
 
 extern DumpOptions *NewDumpOptions(void);
+extern void InitDumpOptions(DumpOptions *opts);
 extern DumpOptions *dumpOptionsFromRestoreOptions(RestoreOptions *ropt);
 
 /* Rearrange and filter TOC entries */

src/bin/pg_dump/pg_backup_archiver.c

@@ -109,23 +109,27 @@ static void mark_create_done(ArchiveHandle *AH, TocEntry *te);
 static void inhibit_data_for_failed_table(ArchiveHandle *AH, TocEntry *te);
 
 /*
- * Allocate a new DumpOptions block.
- * This is mainly so we can initialize it, but also for future expansion.
- * We pg_malloc0 the structure, so we don't need to initialize whatever is
- * 0, NULL or false anyway.
+ * Allocate a new DumpOptions block containing all default values.
  */
 DumpOptions *
 NewDumpOptions(void)
 {
-	DumpOptions *opts;
+	DumpOptions *opts = (DumpOptions *) pg_malloc(sizeof(DumpOptions));
 
-	opts = (DumpOptions *) pg_malloc0(sizeof(DumpOptions));
+	InitDumpOptions(opts);
+	return opts;
+}
 
+/*
+ * Initialize a DumpOptions struct to all default values
+ */
+void
+InitDumpOptions(DumpOptions *opts)
+{
+	memset(opts, 0, sizeof(DumpOptions));
 	/* set any fields that shouldn't default to zeroes */
 	opts->include_everything = true;
 	opts->dumpSections = DUMP_UNSECTIONED;
-
-	return opts;
 }
 
 /*