ci: fix -usecache for programs using thirdparty C libs

cmd/tools/vtest-all.v

@@ -5,10 +5,10 @@ import term
 import time
 
 const (
-	vexe = os.getenv('VEXE')
-	vroot = os.dir(vexe)
+	vexe        = os.getenv('VEXE')
+	vroot       = os.dir(vexe)
 	args_string = os.args[1..].join(' ')
-	vargs = args_string.all_before('test-all')
+	vargs       = args_string.all_before('test-all')
 )
 
 fn main() {
@@ -49,6 +49,14 @@ mut:
 
 fn get_all_commands() []Command {
 	mut res := []Command{}
+	res << Command{
+		line: '$vexe examples/hello_world.v'
+		okmsg: 'V can compile hello world.'
+	}
+	res << Command{
+		line: '$vexe -o vtmp cmd/v'
+		okmsg: 'V can compile itself.'
+	}
 	res << Command{
 		line: '$vexe $vargs -progress test-cleancode'
 		okmsg: 'All important .v files are invariant when processed with `v fmt`'
@@ -78,6 +86,13 @@ fn get_all_commands() []Command {
 		line: '$vexe install nedpals.args'
 		okmsg: '`v install` works.'
 	}
+	// NB: test that a program that depends on thirdparty libraries with its
+	// own #flags (tetris depends on gg, which uses sokol) can be compiled
+	// with -usecache:
+	res << Command{
+		line: '$vexe -usecache examples/tetris/tetris.v'
+		okmsg: '`v -usecache` works.'
+	}
 	$if macos {
 		res << Command{
 			line: '$vexe -o v.c cmd/v && cc -Werror v.c && rm -rf v.c'