Move alloca, fork, const, and big endian checks to RTS configure

All of this should boil down to `AC_DEFINE` not `AC_SUBST`, so it
belongs in the RTS configure and should be safe to move without
modification.

configure.ac

@@ -978,23 +978,6 @@ AC_SUBST([UseLibdl],[$HaveLibdl])
 dnl ** check whether we have dlinfo
 AC_CHECK_FUNCS([dlinfo])
 
-dnl --------------------------------------------------
-dnl * Miscellaneous feature tests
-dnl --------------------------------------------------
-
-dnl ** can we get alloca?
-AC_FUNC_ALLOCA
-
-dnl ** working vfork?
-AC_FUNC_FORK
-
-dnl ** determine whether or not const works
-AC_C_CONST
-
-dnl ** are we big endian?
-AC_C_BIGENDIAN
-FPTOOLS_FLOAT_WORD_ORDER_BIGENDIAN
-
 dnl ** check for leading underscores in symbol names
 FP_LEADING_UNDERSCORE
 AC_SUBST([LeadingUnderscore], [`echo $fptools_cv_leading_underscore | sed 'y/yesno/YESNO/'`])

rts/configure.ac

@@ -33,6 +33,23 @@ GHC_CONVERT_PLATFORM_PARTS([host], [Host])
 FPTOOLS_SET_PLATFORM_VARS([host], [Host])
 FPTOOLS_SET_HASKELL_PLATFORM_VARS([Host])
 
+dnl --------------------------------------------------
+dnl * Miscellaneous feature tests
+dnl --------------------------------------------------
+
+dnl ** can we get alloca?
+AC_FUNC_ALLOCA
+
+dnl ** working vfork?
+AC_FUNC_FORK
+
+dnl ** determine whether or not const works
+AC_C_CONST
+
+dnl ** are we big endian?
+AC_C_BIGENDIAN
+FPTOOLS_FLOAT_WORD_ORDER_BIGENDIAN
+
 dnl ** check for leading underscores in symbol names
 if test "$CABAL_FLAG_leading_underscore" = 1; then
    AC_DEFINE([LEADING_UNDERSCORE], [1], [Define to 1 if C symbols have a leading underscore added by the compiler.])