iverilog: fix implicit declaration error

* fix build on macOS <10.7

Co-authored-by: Sergey Fedorov <barracuda@macos-powerpc.org>

science/iverilog/Portfile

@@ -2,11 +2,15 @@
 PortSystem          1.0
 PortGroup           github 1.0
 PortGroup           compiler_blacklist_versions 1.0
+PortGroup           legacysupport 1.1
+
+# strndup
+legacysupport.newest_darwin_requires_legacy 10
 
 github.setup        steveicarus iverilog 20250103 s
 github.tarball_from archive
 
-revision            0
+revision            1
 set major           12
 set minor           0
 
@@ -47,6 +51,9 @@ configure.ldflags-append -Wl,-rpath,${prefix}/lib
 
 patchfiles-append patch-vvp-Makefile.in.diff
 
+# main.c:1065:17: error: implicit declaration of function '_NSGetExecutablePath' [-Wimplicit-function-declaration]
+patchfiles-append patch-fix-headers.diff
+
 platform darwin {
     #under MacOS, this is needed, the library references were incorrect as-is
     configure.cxxflags-append -fPIC

science/iverilog/files/patch-fix-headers.diff

@@ -0,0 +1,13 @@
+--- driver/main.c.orig
++++ driver/main.c
+@@ -81,6 +81,10 @@
+ extern const char*optarg;
+ #endif
+ 
++#if defined(__APPLE__)
++#include <mach-o/dyld.h>
++#endif
++
+ #if !defined(WIFEXITED)
+ # define WIFEXITED(rc) ((rc&0x7f) == 0)
+ #endif