replace leading _ for private symbols with keyword hide

examples/programs/mem_allocator/typed_alloc.bro

@@ -1,30 +1,30 @@
 mem :: import "@std/mem"
 
-_probe_count func(context ?*mut anyopaque) void {
+hide probe_count func(context ?*mut anyopaque) void {
 	if context |raw| {
 		counts *mut usize :: ptrcast!(usize, raw)
 		counts[0] += 1
 	}
 }
 
-_probe_alloc func(context ?*mut anyopaque, _ usize, _ usize) ?*mut u8 {
-	_probe_count(context)
+hide probe_alloc func(context ?*mut anyopaque, _ usize, _ usize) ?*mut u8 {
+	probe_count(context)
 	return none
 }
 
-_probe_realloc func(context ?*mut anyopaque, _ ?*mut u8, _ usize, _ usize, _ usize) ?*mut u8 {
-	_probe_count(context)
+hide probe_realloc func(context ?*mut anyopaque, _ ?*mut u8, _ usize, _ usize, _ usize) ?*mut u8 {
+	probe_count(context)
 	return none
 }
 
-_probe_free func(context ?*mut anyopaque, _ ?*mut u8, _ usize, _ usize) void {
-	_probe_count(context)
+hide probe_free func(context ?*mut anyopaque, _ ?*mut u8, _ usize, _ usize) void {
+	probe_count(context)
 }
 
-_probe_vtable mem.AllocatorVTable :: mem.AllocatorVTable {
-	alloc = _probe_alloc,
-	realloc = _probe_realloc,
-	free = _probe_free,
+hide probe_vtable mem.AllocatorVTable :: mem.AllocatorVTable {
+	alloc = probe_alloc,
+	realloc = probe_realloc,
+	free = probe_free,
 }
 
 typed_allocator_test func() i32 {
@@ -34,11 +34,11 @@ typed_allocator_test func() i32 {
 	second_calls [1]mut usize = [0]
 	first_allocator mem.Allocator :: mem.Allocator {
 		context = (&first_calls).ptr,
-		vtable = &_probe_vtable,
+		vtable = &probe_vtable,
 	}
 	second_allocator mem.Allocator :: mem.Allocator {
 		context = (&second_calls).ptr,
-		vtable = &_probe_vtable,
+		vtable = &probe_vtable,
 	}
 
 	_ = mem.raw_alloc(first_allocator, 1, 1)