Make liblist an extern to fix dtksh compile (#108)

The liblist variable needs to be an extern for dtksh to build.
Quote from CDE developer Chase:
we use an old function that no longer appears in kornshell,
sh_getliblist, it seems to be replaced by the function sh_getlib,
which is fine, but it seems to return a "Shbltin_f" type, which I
can't seem to find any information on what it is. We need the void
pointer dlsym provides for some widget init stuff, I tried making
liblist an extern, but it kept giving me an error about libcomp_t
being undefined.

src/cmd/ksh93/bltins/typeset.c,
src/cmd/ksh93/include/shell.h:
- Fix the compiler error reported above by moving the type definition
  for Libcomp_t to shell.h.
- Make liblist an extern since findsym.c in dtksh needs it to build.
  The old sh_getliblist function doesn't need to be reintroduced
  since the only purpose it served was to workaround the problem
  of liblist being a static variable. Now that liblist is an extern,
  dtksh fsym can use liblist directly to avoid sh_getliblist.

dtksh findsym.c:
https://sourceforge.net/p/cdesktopenv/code/ci/2.3.2/tree/cde/programs/dtksh/findsym.c

src/cmd/ksh93/bltins/typeset.c

@@ -904,18 +904,9 @@ static int     setall(char **argv,register int flag,Dt_t *troot,struct tdata *tp
 
 typedef void (*Libinit_f)(int,void*);
 
-typedef struct Libcomp_s
-{
-	void*		dll;
-	char*		lib;
-	dev_t		dev;
-	ino_t		ino;
-	unsigned int	attr;
-} Libcomp_t;
-
 #define GROWLIB	4
 
-static Libcomp_t	*liblist;
+Libcomp_t	*liblist;
 static int		nlib;
 static int		maxlib;
 

src/cmd/ksh93/include/shell.h

@@ -150,6 +150,17 @@ struct Shell_s
 #endif /* _SH_PRIVATE */
 };
 
+/* used for builtins */
+typedef struct Libcomp_s
+{
+	void*		dll;
+	char*		lib;
+	dev_t		dev;
+	ino_t		ino;
+	unsigned int	attr;
+} Libcomp_t;
+extern Libcomp_t *liblist;
+
 /* flags for sh_parse */
 #define SH_NL		1	/* Treat new-lines as ; */
 #define SH_EOF		2	/* EOF causes syntax error */