Patch fixes building on hurd-i386, kfreebsd-i386 and kfreebsd-amd64
architectures.

--- a/configure
+++ b/configure
@@ -8329,7 +8329,7 @@
 	        fi
 	    fi
 	    ;;
-	Linux*)
+	Linux*|GNU*)
 	    SHLIB_CFLAGS="-fPIC"
 	    SHLIB_LD_LIBS='${LIBS}'
 	    SHLIB_SUFFIX=".so"
--- a/tclconfig/tcl.m4
+++ b/tclconfig/tcl.m4
@@ -1440,7 +1440,7 @@
 	        fi
 	    fi
 	    ;;
-	Linux*)
+	Linux*|GNU*)
 	    SHLIB_CFLAGS="-fPIC"
 	    SHLIB_LD_LIBS='${LIBS}'
 	    SHLIB_SUFFIX=".so"