Fix build on Solaris 10 (bug#75451)

* autogen.sh: Avoid bashism.
* configure.ac (AC_PROG_AWK): Use.
* src/Makefile.in (AWK): Set.
(dmpstruct.h): Use "$(AWK)", not "awk".
* src/dired.c (DT_UNKNOWN, DT_DIR, DT_LNK): Define all three constants
or none of them.

autogen.sh

@@ -115,7 +115,7 @@ do_check=true
 do_autoconf=false
 do_git=false
 
-for arg; do
+for arg in "$@"; do
     case $arg in
       --help)
 	exec echo "$0: usage: $0 [--no-check] [target...]

configure.ac

@@ -2004,6 +2004,8 @@ ARCH_INDEPENDENT_CONFIG_FILES([src/verbose.mk])
 
 dnl Some other nice autoconf tests.
 AC_PROG_INSTALL
+dnl use "gawk" where possible
+AC_PROG_AWK
 dnl These are commented out, since gl_EARLY and/or Autoconf already does them.
 dnl AC_PROG_MKDIR_P
 dnl if test "x$RANLIB" = x; then

src/Makefile.in

@@ -60,6 +60,7 @@ LDFLAGS = @LDFLAGS@
 EXEEXT = @EXEEXT@
 version = @version@
 MKDIR_P = @MKDIR_P@
+AWK = @AWK@
 # Don't use LIBS.  configure puts stuff in it that either shouldn't be
 # linked with Emacs or is duplicated by the other stuff below.
 # LIBS = @LIBS@
@@ -543,7 +544,7 @@ pdumper.o: dmpstruct.h
 endif
 dmpstruct.h: $(srcdir)/dmpstruct.awk
 dmpstruct.h: $(libsrc)/make-fingerprint$(EXEEXT) $(dmpstruct_headers)
-	$(AM_V_GEN)POSIXLY_CORRECT=1 awk -f $(srcdir)/dmpstruct.awk \
+	$(AM_V_GEN)POSIXLY_CORRECT=1 $(AWK) -f $(srcdir)/dmpstruct.awk \
 		$(dmpstruct_headers) > $@
 
 AUTO_DEPEND = @AUTO_DEPEND@

src/dired.c

@@ -79,7 +79,17 @@ dirent_namelen (struct dirent *dp)
 }
 
 #ifndef HAVE_STRUCT_DIRENT_D_TYPE
-enum { DT_UNKNOWN, DT_DIR, DT_LNK };
+#if !defined (DT_UNKNOWN) && !defined (DT_DIR) && !defined (DT_LNK)
+enum {
+  DT_UNKNOWN,
+  DT_DIR,
+  DT_LNK,
+};
+#elif defined (DT_UNKNOWN) && defined (DT_DIR) && defined (DT_LNK)
+/* Nothing to do here, all three are defined as macros.  */
+#elif defined (DT_UNKNOWN) || defined (DT_DIR) || defined (DT_LNK)
+#error "Cannot determine DT_UNKNOWN, DT_DIR, DT_LNK"
+#endif
 #endif
 
 /* Return the file type of DP.  */