Emacs 26.2 etags.c warning

[Jeffrey Walton]

Hi Everyone,

I'm building Emacs 26.2 from sources. I use '-DNDEBUG -g2 -O3' as my
base CFLAGS. It is producing a warning when compiling etags.c.

gcc     -I. -I../src -I../lib -I. -I./../src -I./../lib
-L/usr/local/lib64 -Wl,-R,/usr/local/lib64 -Wl,--enable-new-dtags
-I/usr/local/include -DNDEBUG -g2 -O2 -march=native -fPIC
-DEMACS_NAME="\"GNU Emacs\"" -DVERSION="\"26.2\"" -o etags etags.c
regex.o  ../lib/libgnu.a
etags.c:88: warning: "NDEBUG" redefined
 #  define NDEBUG  /* disable assert */

Maybe guard the define?

Hat tip for building a release version of the software out of the box.

Jeff