Update zconf.h prefixes to match zlib v1.2.12 update

Historically Qt has used `Z_PREFIX` within zconf.h of its bundled zlib
copy to prefix all zlib symbols with `z_` in order to prevent clashes
with a potential system install of the library when linking statically;
however, v1.2.12 introduced 3 new functions that were erroneously not
accounted for in the upstream repository:

- crc32_combine_gen
- crc32_combine_gen64
- crc32_combine_op

`403020` updated our bundled zlib to this new version and therefore
Qt has inherited this oversight, now clashing with external zlib
builds.

Manually add prefix macro definitions for these three symbols to
restore built-in zlib to its previous clash free state while waiting
for the issue to be addressed upstream.

Pick-to: 6.4 6.3 6.2 5.15
Change-Id: I83f88109a08cf7e7117f1c94b4557a2c36f519c3
Reviewed-by: Kai Koehne <kai.koehne@qt.io>

src/3rdparty/zlib/qtpatches.diff

@@ -54,7 +54,17 @@ diff -ruN orig/zconf.h src/zconf.h
  /*
   * If you *really* need a unique prefix for all types and library functions,
   * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
-@@ -136,6 +139,7 @@
+@@ -38,6 +41,9 @@
+ #  define crc32                 z_crc32
+ #  define crc32_combine         z_crc32_combine
+ #  define crc32_combine64       z_crc32_combine64
++#  define crc32_combine_gen     z_crc32_combine_gen
++#  define crc32_combine_gen64   z_crc32_combine_gen64
++#  define crc32_combine_op      z_crc32_combine_op
+ #  define crc32_z               z_crc32_z
+ #  define deflate               z_deflate
+ #  define deflateBound          z_deflateBound
+@@ -136,6 +142,7 @@
  #  endif
  #  define zlibCompileFlags      z_zlibCompileFlags
  #  define zlibVersion           z_zlibVersion
@@ -62,7 +72,7 @@ diff -ruN orig/zconf.h src/zconf.h
  
  /* all zlib typedefs in zlib.h and zconf.h */
  #  define Byte                  z_Byte
-@@ -431,7 +435,7 @@
+@@ -431,7 +438,7 @@
     typedef unsigned long z_crc_t;
  #endif
  

src/3rdparty/zlib/src/zconf.h

@@ -41,6 +41,9 @@
 #  define crc32                 z_crc32
 #  define crc32_combine         z_crc32_combine
 #  define crc32_combine64       z_crc32_combine64
+#  define crc32_combine_gen     z_crc32_combine_gen
+#  define crc32_combine_gen64   z_crc32_combine_gen64
+#  define crc32_combine_op      z_crc32_combine_op
 #  define crc32_z               z_crc32_z
 #  define deflate               z_deflate
 #  define deflateBound          z_deflateBound