Move all knowledge that $(MAINOBJ) is built in the Modules/ directory
into Makefile.pre.in; the configure script will only determine the basename
of the file.

This fixes installation of a Python built using C++, reported by Greg
Wilson.
diff --git a/configure b/configure
index b7ad64a..bab3fff 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 
-# From configure.in Revision: 1.207 
+# From configure.in Revision: 1.208 
 
 # Guess values for system-dependent variables and create Makefiles.
 # Generated automatically using autoconf version 2.13 
@@ -717,7 +717,7 @@
 
 
 
-MAINOBJ=Modules/python.o
+MAINOBJ=python.o
 echo $ac_n "checking for --with-cxx=<compiler>""... $ac_c" 1>&6
 echo "configure:723: checking for --with-cxx=<compiler>" >&5
 # Check whether --with-cxx or --without-cxx was given.
@@ -729,7 +729,7 @@
 	no)	CXX=
 		with_cxx=no;;
 	*)	CXX=$withval
-		MAINOBJ=Modules/ccpython.o
+		MAINOBJ=ccpython.o
 		with_cxx=$withval;;
 	esac
 else
@@ -5041,7 +5041,7 @@
 int main() {
 
 /* Ultrix mips cc rejects this.  */
-typedef int charset[2]; const charset x = {0,0};
+typedef int charset[2]; const charset x;
 /* SunOS 4.1.1 cc rejects this.  */
 char const *const *ccp;
 char **p;