I suggest the following change, to avoid unnecessary temporary files at build time.

Index: Makefile.in
==================================================================
--- Makefile.in
+++ Makefile.in
@@ -36,14 +36,12 @@

 # Create a C-source-ified version of the script resources
 # for TclTLS so that we only need a single file to enable
 # this extension
 tls.tcl.h: @srcdir@/tls.tcl Makefile
-       od -A n -v -t xC < '@srcdir@/tls.tcl' > tls.tcl.h.new.1
-       sed 's@  *@@g;s@..@0x&, @g' < tls.tcl.h.new.1 > tls.tcl.h.new.2
-       rm -f tls.tcl.h.new.1
-       mv tls.tcl.h.new.2 tls.tcl.h
+       od -A n -v -t xC < '@srcdir@/tls.tcl' | \
+       sed 's@  *@@g;s@..@0x&, @g' > tls.tcl.h

 # Create default DH parameters
 dh_params.h: @srcdir@/gen_dh_params Makefile
        @srcdir@/gen_dh_params @GEN_DH_PARAMS_ARGS@ > dh_params.h.new
        mv dh_params.h.new dh_params.h