patch 8.0.0755: terminal window does not have colors in the GUI

Problem:    Terminal window does not have colors in the GUI.
Solution:   Lookup the GUI color.
diff --git a/src/proto/gui_gtk_x11.pro b/src/proto/gui_gtk_x11.pro
index 124e2ae..aaf710c 100644
--- a/src/proto/gui_gtk_x11.pro
+++ b/src/proto/gui_gtk_x11.pro
@@ -36,6 +36,7 @@
 char_u *gui_mch_get_fontname(GuiFont font, char_u *name);
 void gui_mch_free_font(GuiFont font);
 guicolor_T gui_mch_get_color(char_u *name);
+guicolor_T gui_mch_get_rgb_color(int r, int g, int b);
 void gui_mch_set_fg_color(guicolor_T color);
 void gui_mch_set_bg_color(guicolor_T color);
 void gui_mch_set_sp_color(guicolor_T color);
@@ -53,7 +54,7 @@
 void gui_mch_update(void);
 int gui_mch_wait_for_chars(long wtime);
 void gui_mch_flush(void);
-void gui_mch_clear_block(int row1, int col1, int row2, int col2);
+void gui_mch_clear_block(int row1arg, int col1arg, int row2arg, int col2arg);
 void gui_mch_clear_all(void);
 void gui_mch_delete_lines(int row, int num_lines);
 void gui_mch_insert_lines(int row, int num_lines);