[PATCH] newlib: docs: print the function index

The generated function documentation makes sure to include entries for
every function in the function index via @findex, but then the manuals
forget to actually print the index.
---
 newlib/libc/libc.texi | 4 ++++
 newlib/libm/libm.texi | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/newlib/libc/libc.texi b/newlib/libc/libc.texi
index c6aeab2278f1..ea96f86b6e3f 100644
--- a/newlib/libc/libc.texi
+++ b/newlib/libc/libc.texi
@@ -410,6 +410,10 @@ usage as the ANSI C version from @file{stdarg.h}.
 @unnumbered Document Index
 @printindex cp
 
+@node Function Index
+@unnumbered Function Index
+@printindex fn
+
 @tex
 % I think something like @@colophon should be in texinfo.  In the
 % meantime:
diff --git a/newlib/libm/libm.texi b/newlib/libm/libm.texi
index 943262d055ae..26c393df8c6b 100644
--- a/newlib/libm/libm.texi
+++ b/newlib/libm/libm.texi
@@ -121,10 +121,15 @@ This makes it thread safe, and therefore reentrant.
 Currently, the full set of long double math functions is only provided
 on platforms where long double equals double.
 For such platforms, the long double math functions are implemented as calls to the double versions.
+
 @node Document Index
 @unnumbered Document Index
 @printindex cp
 
+@node Function Index
+@unnumbered Function Index
+@printindex fn
+
 @tex
 % I think something like @@colophon should be in texinfo.  In the
 % meantime:
-- 
2.43.0