solaris: Use versioning scripts instead of -Bsymbolic

-Bsymbolic causes a lot of "ld: warning: symbol referencing errors"
warnings. It's quite easy to add the symbol versioning script, we just need a
slightly different parameter name.

Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/20220823083436.whtntk3bn3qpnvmb@awork3.anarazel.de
Discussion: https://postgr.es/m/7dae5979-c6c0-cec5-7a36-76a85aa8053d@enterprisedb.com

src/Makefile.shlib

@@ -188,10 +188,15 @@ ifeq ($(PORTNAME), linux)
 endif
 
 ifeq ($(PORTNAME), solaris)
-  LINK.shared		= $(COMPILER) -shared -Wl,-Bsymbolic
+  LINK.shared		= $(COMPILER) -shared
   ifdef soname
     LINK.shared	+= -Wl,-soname,$(soname)
   endif
+  BUILD.exports		= ( echo '{ global:'; $(AWK) '/^[^\#]/ {printf "%s;\n",$$1}' $<; echo ' local: *; };' ) >$@
+  exports_file		= $(SHLIB_EXPORTS:%.txt=%.list)
+  ifneq (,$(exports_file))
+    LINK.shared		+= -Wl,-M$(exports_file)
+  endif
 endif
 
 ifeq ($(PORTNAME), cygwin)