8349214: Improve size optimization flags for MSVC builds

Reviewed-by: djelinski, ihse

Author: MBaesken

make/autoconf/flags-cflags.m4

@@ -347,7 +347,7 @@ AC_DEFUN([FLAGS_SETUP_OPTIMIZATION],
     C_O_FLAG_DEBUG="-Od"
     C_O_FLAG_DEBUG_JVM=""
     C_O_FLAG_NONE="-Od"
-    C_O_FLAG_SIZE="-Os"
+    C_O_FLAG_SIZE="-O1"
   fi
 
   # Now copy to C++ flags