tdf#122218: Hack to avoid blurry text with macOS SDK 10.15

...by setting the LC_VERSION_MIN_MACOSX load command's sdk value to n/a in the
soffice executable.

See <https://bugs.documentfoundation.org/show_bug.cgi?id=122218#c167> for how
this helps, even though I have no idea why it helps.

(Adding that -platform_version linker option appears to generate warnings like

> ld: warning: passed two min versions (10.13.0, 10.13) for platform macOS. Using 10.13.

but which are probably harmless.)

Change-Id: I043498c7ff2d148d4a7e1e0e9d46241b638f2eba
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/88667
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

desktop/Executable_soffice_bin.mk

@@ -29,6 +29,13 @@ $(eval $(call gb_Executable_set_ldflags,\
     $(filter-out -bind_at_load,$$(LDFLAGS)) \
 ))
 
+# At least when building against SDK 10.15, changing the LC_VERSION_MIN_MACOSX load command's sdk
+# value from 10.15 to "n/a" (i.e., 0.0) is necessary to avoid blurry text in the LO UI:
+$(eval $(call gb_Executable_add_ldflags,soffice_bin, \
+    -Xlinker -platform_version -Xlinker macos -Xlinker $(MAC_OS_X_VERSION_MIN_REQUIRED_DOTS) \
+        -Xlinker 0.0 \
+))
+
 endif
 
 ifeq ($(OS),WNT)