patch 8.2.2928: the evalfunc.c file is too big

Problem:    The evalfunc.c file is too big.
Solution:   Move float related functionality to a separate file. (Yegappan
            Lakshmanan, closes #8287)
diff --git a/src/Make_ami.mak b/src/Make_ami.mak
index 88b3986..91246d9 100644
--- a/src/Make_ami.mak
+++ b/src/Make_ami.mak
@@ -117,6 +117,7 @@
 	fileio.c \
 	filepath.c \
 	findfile.c \
+	float.c \
 	fold.c \
 	getchar.c \
 	hardcopy.c \