Rename some examples

examples/free_by_gc/src/main.rs

@@ -0,0 +1,15 @@
+extern crate bdwgc_alloc;
+
+use bdwgc_alloc::Allocator;
+use std::alloc::{GlobalAlloc, Layout};
+
+#[global_allocator]
+static GLOBAL_ALLOCATOR: Allocator = Allocator;
+
+fn main() {
+    unsafe { Allocator::initialize() }
+
+    loop {
+        unsafe { GLOBAL_ALLOCATOR.alloc(Layout::from_size_align(2 ^ 8, 8).unwrap()) };
+    }
+}