Gets _DEFLATE$ and _INFLATE$ to work on macOS.

internal/c/libqb.cpp

@@ -16454,7 +16454,7 @@ void sub_put2(int32 i,int64 offset,void *element,int32 passed){
     #endif
     
     #ifdef DEPENDENCY_ZLIB
-        #ifdef QB64_BACKSLASH_FILESYSTEM //change slashes depending on OS, I guess?  Included by copying audio template, and it works.  (SMcNeill comment)
+        #ifdef QB64_BACKSLASH_FILESYSTEM
             #include "parts\\zlib\\src.c"
         #else
             #include "parts/zlib/src.c"

internal/c/parts/zlib/src.c

@@ -1,8 +1,10 @@
 #ifdef QB64_WINDOWS
-    #include "download\zlib.h"
+  #include "download\\zlib.h"
+#else
+  #include <zlib.h>
 #endif
+
   qbs *func__deflate(qbs *text){
-    #ifdef QB64_WINDOWS
         uLongf filesize = (uint32)text->len;  //length of the text
         uLongf compsize = compressBound(filesize);
         unsigned char *dest = (unsigned char *)malloc(compsize);
@@ -11,13 +13,9 @@
         memcpy(ret->chr, dest, compsize);
         free(dest);
         return ret;
-    #else
-        return text;
-    #endif
   }
 
   qbs *func__inflate(qbs *text, int64 originalsize, int32 passed){
-  #ifdef QB64_WINDOWS
         int32 result=0;
         if (passed==1){
             uLongf uncompsize = originalsize;
@@ -41,7 +39,4 @@
             free(dest);
             return ret;
         }
-  #else
-        return text;
-  #endif
   }

source/qb64.bas

@@ -11971,13 +11971,15 @@ END IF
 
 IF DEPENDENCY(DEPENDENCY_ZLIB) THEN
     defines$ = defines$ + defines_header$ + "DEPENDENCY_ZLIB"
-    IF win THEN 'ZLIB is only supported for windows versions so far
+    IF os$ = "WIN" THEN
         d$ = "internal\c\parts\zlib\"
         'rebuild?
         IF _FILEEXISTS(d$ + "os\" + o$ + "\src.a") = 0 THEN
             Build d$ + "os\" + o$
         END IF
         libs$ = libs$ + " " + "parts\zlib\os\" + o$ + "\src.a -lz"
+    ELSE
+        libs$ = libs$ + " -lz"
     END IF
 END IF