configure.ac: Remove some obsolescent macros

AC_C_CONST: current C compilers support const
AC_TYPE_SYGNAL: obsolete when assuming C89 or better
AC_HEADER_STDC: current systems have conforming header files

diff --git a/configure.ac b/configure.ac
index 71589c1df2cf6ab7496b436f27a21aad21cf59b9..7d941f30496b74ee6494b20698d2ec6b6bb22091 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -703,14 +703,7 @@ saved_cflags="$CFLAGS"
 saved_ldflags="$LDFLAGS"
 
 
-# Checks for header files.
-AC_HEADER_STDC
-
-# Checks for typedefs, structures, and compiler characteristics.
-AC_C_CONST
-
 # Checks for library functions.
-AC_TYPE_SIGNAL
 AC_FUNC_MMAP
 
 AC_CHECK_FUNCS(mallinfo)