ghc: Fix build issue

* Fixes: https://trac.macports.org/ticket/74031

lang/ghc/Portfile

@@ -6,7 +6,7 @@ PortGroup           legacysupport 1.1
 
 name                ghc
 version             9.14.1
-revision            2
+revision            3
 categories          lang haskell
 maintainers         {ieee.org:s.t.smith @essandess} openmaintainer
 license             BSD
@@ -458,8 +458,11 @@ if {${name} eq ${subport}} {
         # symbol. Because the compilation process statically links
         # libHSbase.a, we must add these flags to ghc linking.
         # See: ./hadrian/doc/user-settings.md
+        # If ghc-prebuilt links against SDK libiconv symbols:
+        #    -L${configure.sdkroot}/usr/lib
+        # otherwise: -L${prefix}/lib
         build.post_args-append \
-                    "\"stage0.*.ghc.link.opts += -L${configure.sdkroot}/usr/lib\"" \
+                    "\"stage0.*.ghc.link.opts += -L${prefix}/lib\"" \
                     "\"stage1.*.ghc.link.opts += -L${prefix}/lib\"" \
                     "\"stage2.*.ghc.link.opts += -L${prefix}/lib\"" \
                     "\"stage3.*.ghc.link.opts += -L${prefix}/lib\""