build: check -tags nogc

c/pthread/_wrap/pthread_gc.c

@@ -1,11 +0,0 @@
-#define GC_THREADS
-#include <gc.h>
-#include <pthread.h>
-
-int llgoPthreadCreate(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg) {
-    return GC_pthread_create(thread, attr, start_routine, arg);
-}
-
-int llgoPthreadJoin(pthread_t thread, void **retval) {
-    return GC_pthread_join(thread, retval);
-}

c/pthread/pthread.go

@@ -32,6 +32,9 @@ type aThread struct {
 	Unused [8]byte
 }
 
+//llgo:type C
+type RoutineFunc func(c.Pointer) c.Pointer
+
 // Thread represents a POSIX thread.
 type Thread = *aThread
 

c/pthread/pthread_gc.go

@@ -26,7 +26,6 @@ import (
 )
 
 const (
-	LLGoFiles   = "$(pkg-config --cflags bdw-gc): _wrap/pthread_gc.c"
 	LLGoPackage = "link: $(pkg-config --libs bdw-gc); -lgc"
 )
 
@@ -56,8 +55,8 @@ const (
 //
 // See https://man7.org/linux/man-pages/man3/pthread_create.3.html
 //
-//go:linkname Create C.llgoPthreadCreate
-func Create(pthread *Thread, attr *Attr, routine func(c.Pointer) c.Pointer, arg c.Pointer) c.Int
+//go:linkname Create C.GC_pthread_create
+func Create(pthread *Thread, attr *Attr, routine RoutineFunc, arg c.Pointer) c.Int
 
 // The pthread_join() function waits for the thread specified by
 // thread to terminate.  If that thread has already terminated, then
@@ -77,5 +76,5 @@ func Create(pthread *Thread, attr *Attr, routine func(c.Pointer) c.Pointer, arg
 //
 // See https://man7.org/linux/man-pages/man3/pthread_join.3.html
 //
-//go:linkname Join C.llgoPthreadJoin
+//go:linkname Join C.GC_pthread_join
 func Join(thread Thread, retval *c.Pointer) c.Int

c/pthread/pthread_nogc.go

@@ -56,7 +56,7 @@ const (
 // See https://man7.org/linux/man-pages/man3/pthread_create.3.html
 //
 //go:linkname Create C.pthread_create
-func Create(pthread *Thread, attr *Attr, routine func(c.Pointer) c.Pointer, arg c.Pointer) c.Int
+func Create(pthread *Thread, attr *Attr, routine RoutineFunc, arg c.Pointer) c.Int
 
 // The pthread_join() function waits for the thread specified by
 // thread to terminate.  If that thread has already terminated, then