Remove relics of objc_namespace script

objc_namespace.sh had been removed from Qt, as it stopped working with
recent XCode, however the qmake prf file was still around and
referencing it. We can remove the relic as well

Amends 6404714183

Task-number: QTBUG-132398
Pick-to: 6.8 6.9 6.10
Change-Id: I9fc63751a5e3c118b9f1e13799920784d11d18d9
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

mkspecs/features/mac/unsupported/objc_namespace.prf

@@ -1,50 +0,0 @@
-#
-#  W A R N I N G
-#  -------------
-#
-# This file is not part of the Qt API.  It exists purely as an
-# implementation detail.  It may change from version to version
-# without notice, or even be removed.
-#
-# We mean it.
-#
-
-# The Objective-C runtime will complain when loading a binary that
-# introduces as class name that already exists in the global namespace.
-# This may happen when linking Qt statically into a plugin, and then
-# loading more than two plugins into the same host, both using Qt.
-#
-# We work around this by doing a bit of post-processing on the final
-# binary, adding new suffixed class name entries to the __objc_classname
-# section of the __TEXT segment, and then patching the class_ro_t
-# entries to point to the newly added class names.
-#
-# By linking the binary between these two steps we avoid having to
-# manually remap all the offsets in the Mach-O binary due to the
-# added class names, instead relying on the linker to do this
-# for us by linking in an assembly file with the added names.
-
-objc_namespace_script = $$clean_path($$PWD/../../data/mac/objc_namespace.sh)
-
-isEmpty(QMAKE_OBJC_NAMESPACE_SUFFIX) {
-    QMAKE_OBJC_NAMESPACE_SUFFIX = $$TARGET
-    !isEmpty(QMAKE_TARGET_BUNDLE_PREFIX): \
-        QMAKE_OBJC_NAMESPACE_SUFFIX = $${QMAKE_TARGET_BUNDLE_PREFIX}.$${QMAKE_OBJC_NAMESPACE_SUFFIX}
-}
-
-QMAKE_LFLAGS += \
-    -Wobjc_namespace,--target=$$shell_quote($$TARGET) \
-    -Wobjc_namespace,--suffix=$$shell_quote($$QMAKE_OBJC_NAMESPACE_SUFFIX) \
-    -Wobjc_namespace,--original_ld=$$shell_quote($$QMAKE_LINK)
-
-!isEmpty(QMAKE_OBJC_NAMESPACE_EXCLUDE): \
-    QMAKE_LFLAGS += -Wobjc_namespace,--exclude_list=$$shell_quote($$QMAKE_OBJC_NAMESPACE_EXCLUDE)
-!isEmpty(QMAKE_OBJC_NAMESPACE_EXCLUDE_REGEX) {
-    equals(MAKEFILE_GENERATOR, UNIX): \
-        QMAKE_OBJC_NAMESPACE_EXCLUDE_REGEX ~= s/\\$/\$\$/
-    QMAKE_LFLAGS += -Wobjc_namespace,--exclude_regex=$$shell_quote($$QMAKE_OBJC_NAMESPACE_EXCLUDE_REGEX)
-}
-
-slient: QMAKE_LFLAGS += -Wobjc_namespace,--silent=1
-
-QMAKE_LINK = $$objc_namespace_script