RTS configure: Move over misc function checks

These are for general use in the RTS.

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.

Progress towards #17191

configure.ac

@@ -1044,8 +1044,6 @@ dnl ** check for eventfd which is needed by the I/O manager
 AC_CHECK_HEADERS([sys/eventfd.h])
 AC_CHECK_FUNCS([eventfd])
 
-AC_CHECK_FUNCS([getpid getuid raise])
-
 GHC_ADJUSTORS_METHOD([Target])
 AC_SUBST([UseLibffiForAdjustors])
 

rts/configure.ac

@@ -33,6 +33,8 @@ GHC_CONVERT_PLATFORM_PARTS([host], [Host])
 FPTOOLS_SET_PLATFORM_VARS([host], [Host])
 FPTOOLS_SET_HASKELL_PLATFORM_VARS([Host])
 
+AC_CHECK_FUNCS([getpid getuid raise])
+
 dnl ** Check for __thread support in the compiler
 AC_MSG_CHECKING(for __thread support)
 AC_COMPILE_IFELSE(