Add the AM_CONDITIONAL for the windows build (OMPI_NEED_WINDOWS_REPLACEMENTS).

This commit was SVN r8537.

configure.ac

@@ -261,6 +261,11 @@ ompi_show_title "Compiler and preprocessor tests"
 
 OMPI_SETUP_CC
 
+# If we build on a windows environment with the windows compiler and linker
+# then we need some translation functions from the opal/win32 directory.
+AM_CONDITIONAL(OMPI_NEED_WINDOWS_REPLACEMENTS,
+               test "$ompi_cv_c_compiler_vendor" = "microsoft" )
+
 #
 # Check for some types
 #