zlib.sh: drop convoluted local fix for upstream RC build bug [ci skip]

Use a less convoluted, shorter workaround instead.

It appears that zlib is either uninterested in accepting bugfixes, or
thinks that the correct fix might be wrong, or may break compatibility
with 20+ year old CMake releases, or possibly breaking some old,
undefined system, or may hit a niche bug somebody heard about, and/or
just afraid to make any changes, or even let its CI run on them.

PR (abandoned): madler/zlib#677

_build.sh

@@ -722,22 +722,6 @@ build_single_target() {
   export NM="${_BINUTILS_PREFIX}nm${_BINUTILS_SUFFIX}"
   export RANLIB="${_BINUTILS_PREFIX}ranlib${_BINUTILS_SUFFIX}"
 
-  # In some environments, we need to pair up llvm-windres with the mingw-w64
-  # include dir, and/or we need to pass it the target platform. Some builds
-  # do not (yet) support adding custom options. Add a wrapper for these
-  # builds that calls llvm-windres with the necessary custom options.
-  export _RC_WRAPPER=''
-  if [ "${_CC}" = 'llvm' ] && \
-     [ "${_TOOLCHAIN}" != 'llvm-mingw' ] && \
-     [ -n "${_RCFLAGS_GLOBAL}" ]; then
-    _RC_WRAPPER="$(pwd)/llvm-windres-wrapper"
-    {
-      echo '#!/bin/sh -e'
-      echo "'${RC}' ${_RCFLAGS_GLOBAL} \"\$@\""
-    } > "${_RC_WRAPPER}"
-    chmod +x "${_RC_WRAPPER}"
-  fi
-
   # ar wrapper to normalize created libs
   if [ "${CW_DEV_CROSSMAKE_REPRO:-}" = '1' ]; then
     export AR_NORMALIZE

zlib.sh

@@ -22,17 +22,6 @@ _VER="$1"
     options="${options} -DBUILD_SHARED_LIBS=OFF"
     options="${options} -DZLIB_COMPAT=ON"
     options="${options} -DZLIB_ENABLE_TESTS=OFF"
-  else
-    # Unset this to use an alternative workaround which does not need our
-    # _RC_WRAPPER trickery:
-    zlib_use_rc_wrapper='1'
-
-    if [ "${zlib_use_rc_wrapper}" = '1' ]; then
-      # FIXME (upstream): zlib v1.3 prevents passing custom RCFLAGS to
-      #                   the RC command. Use our wrapper as a workaround.
-      #                   PR: https://github.com/madler/zlib/pull/677
-      [ -n "${_RC_WRAPPER}" ] && export RC="${_RC_WRAPPER}"
-    fi
   fi
 
   # shellcheck disable=SC2086
@@ -42,11 +31,10 @@ _VER="$1"
 
   make --directory="${_BLDDIR}" --jobs="${_JOBS}" install "DESTDIR=$(pwd)/${_PKGDIR}"
 
-  if [ "${_NAM}" = 'zlib' ] && \
-     [ "${zlib_use_rc_wrapper}" != '1' ]; then
-    # Building shared lib has issues compiling resources:
-    #   PR: https://github.com/madler/zlib/pull/677
-    # Workaround to build static only and install manually:
+  if [ "${_NAM}" = 'zlib' ]; then
+    # zlib's RC compilation is broken as of v1.3 (2023-08-18) with broken CMake
+    # option to disable shared libs. `install` wants to build all targets.
+    # Workaround: Build static only and install manually.
     make --directory="${_BLDDIR}" --jobs="${_JOBS}" zlibstatic
 
     mkdir -p "${_PP}/include"