build,win: replace LTCG with Thin LTO for releases

Author: StefanStojanovic

vcbuild.bat

@@ -187,6 +187,18 @@ goto next-arg
 
 :args-done
 
+if defined build_release (
+  set config=Release
+  set package=1
+  set msi=1
+  set licensertf=1
+  set download_arg="--download=all"
+  set i18n_arg=full-icu
+  set projgen=1
+  set cctest=1
+  set thin_lto=1
+)
+
 :: LTO mutual exclusion
 set lto_count=0
 if defined ltcg       set /a lto_count+=1
@@ -208,18 +220,6 @@ if defined pgo_generate if defined pgo_use (
   exit /b 1
 )
 
-if defined build_release (
-  set config=Release
-  set package=1
-  set msi=1
-  set licensertf=1
-  set download_arg="--download=all"
-  set i18n_arg=full-icu
-  set projgen=1
-  set cctest=1
-  set ltcg=1
-)
-
 if defined msi     set stage_package=1
 if defined package set stage_package=1