Use LTCG on Windows for two targets only.

Telegram/CMakeLists.txt

@@ -1601,6 +1601,17 @@ if (WIN32)
         /DELAYLOAD:wtsapi32.dll
         /DELAYLOAD:propsys.dll
     )
+
+    if (NOT build_win64 AND DESKTOP_APP_SPECIAL_TARGET)
+        target_compile_options(Telegram
+        PRIVATE
+            $<IF:$<CONFIG:Debug>,,/GL>
+        )
+        target_link_options(Telegram
+        PRIVATE
+            $<IF:$<CONFIG:Debug>,,/LTCG>
+        )
+    endif()
 endif()
 
 target_prepare_qrc(Telegram)

Telegram/cmake/td_scheme.cmake

@@ -34,6 +34,14 @@ PUBLIC
     desktop-app::lib_tl
 )
 
+if (WIN32 AND NOT build_win64 AND DESKTOP_APP_SPECIAL_TARGET)
+    target_compile_options(td_scheme
+    PRIVATE
+        $<IF:$<CONFIG:Debug>,,/GL>
+    )
+    set_property(TARGET td_scheme APPEND_STRING PROPERTY STATIC_LIBRARY_OPTIONS "$<IF:$<CONFIG:Debug>,,/LTCG>")
+endif()
+
 if (CMAKE_SYSTEM_PROCESSOR STREQUAL "mips64")
     # Sometimes final linking may fail with error "relocation truncated to fit"
     # due to large scheme size.