builtin,v.pkgconfig: use brew's libgc on macos

Author: spytheman

vlib/builtin/builtin_d_gcboehm.v

@@ -6,11 +6,13 @@ $if windows {
 	#flag -I@VROOT/thirdparty/libgc/include
 	#flag -L@VROOT/thirdparty/libgc
 }
+$if macos {
+	#pkgconfig bdw-gc
+}
 
 #include <gc.h>
 
-#flag linux -lgc
-#flag darwin @VROOT/thirdparty/bdwgc/extra/.libs/gc.o
+#flag -lgc
 
 fn C.GC_MALLOC(n size_t) voidptr
 

vlib/builtin/builtin_notd_gcboehm.v

@@ -9,3 +9,6 @@ fn C.GC_MALLOC(n size_t) voidptr
 fn C.GC_REALLOC(ptr voidptr, n size_t) voidptr
 
 fn C.GC_FREE(ptr voidptr)
+
+// fn C.CHECK_LEAKS()
+fn C.GC_gcollect()

vlib/v/pkgconfig/pkgconfig.v

@@ -13,8 +13,9 @@ const (
 		'/usr/lib64/pkgconfig',
 		'/usr/lib/pkgconfig',
 		'/usr/share/pkgconfig',
+		'/opt/homebrew/lib/pkgconfig',
 	]
-	version       = '0.3.0'
+	version       = '0.3.1'
 )
 
 pub struct Options {