patch 9.0.0491: no good reason to build without the float feature

Problem:    No good reason to build without the float feature.
Solution:   Remove configure check for float and "#ifdef FEAT_FLOAT".
diff --git a/runtime/doc/various.txt b/runtime/doc/various.txt
index ac8b4af..6e4afec 100644
--- a/runtime/doc/various.txt
+++ b/runtime/doc/various.txt
@@ -381,7 +381,7 @@
 N  *+folding*		|folding|
    *+footer*		|gui-footer|
    *+fork*		Unix only: |fork| shell commands
-   *+float*		Floating point support
+T  *+float*		Floating point support  Always enabled since 9.0.0491
 N  *+gettext*		message translations |multi-lang|
 -  *+GUI_Athena*	Unix only: Athena |GUI|
    *+GUI_neXtaw*	Unix only: neXtaw |GUI|