RFC: Changing AC_PROG_CC to AC_PROG_CC_C99 in top level configure

[Nick Clifton]

Hi Guys,

   Given that gcc, gdb and now binutils are all now requiring C99 as a
   minimum version of C, are there any objections to updating
   configure.ac to reflect this ?

Cheers
   Nick

diff --git a/configure.ac b/configure.ac
index a721316d07b..59b4194fb24 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1278,7 +1278,7 @@ else
    WINDMC_FOR_BUILD="\$(WINDMC)"
  fi

-AC_PROG_CC
+AC_PROG_CC_C99
  AC_PROG_CXX

  # We must set the default linker to the linker used by gcc for the correct