compiler: use -lpthread during building v itself.

.github/workflows/ci.yml

@@ -292,7 +292,7 @@ jobs:
     - name: v.c can be compiled and run
       run: |
         ./v -os cross -o /tmp/v.c cmd/v
-        gcc  -g -std=gnu11 -w -o v_from_vc /tmp/v.c  -lm
+        gcc  -g -std=gnu11 -w -o v_from_vc /tmp/v.c  -lm -lpthread
         ls -lart v_from_vc
         ./v_from_vc version
     - name: v_win.c can be compiled and run

Makefile

@@ -48,7 +48,7 @@ ifdef WIN32
 	$(CC) $(CFLAGS) -g -std=c99 -municode -w -o v.exe $(TMPVC)/$(VCFILE) $(LDFLAGS)
 	./v.exe self
 else
-	$(CC) $(CFLAGS) -g -std=gnu11 -w -o v $(TMPVC)/$(VCFILE) $(LDFLAGS) -lm
+	$(CC) $(CFLAGS) -g -std=gnu11 -w -o v $(TMPVC)/$(VCFILE) $(LDFLAGS) -lm -lpthread
 ifdef ANDROID
 	chmod 755 v
 endif

vlib/sync/sync_nix.c.v

@@ -3,6 +3,8 @@
 // that can be found in the LICENSE file.
 module sync
 
+#flag -lpthread
+
 // [init_with=new_mutex] // TODO: implement support for this struct attribute, and disallow Mutex{} from outside the sync.new_mutex() function.
 [ref_only]
 pub struct Mutex {

vlib/v/parser/parser.v

@@ -192,6 +192,11 @@ pub fn parse_files(paths []string, table &table.Table, pref &pref.Preferences, g
 			return q.parsed_ast_files
 		}
 	}
+	if false {
+		// TODO: remove this; it just prevents warnings about unused time and runtime
+		time.sleep_ms(1) 
+		println(runtime.nr_cpus())
+	}
 	// ///////////////
 	mut files := []ast.File{}
 	for path in paths {