Vendor dependencies for 0.3.0 release

vendor/gpu-alloc/src/heap.rs

@@ -0,0 +1,32 @@
+#[derive(Debug)]
+pub(crate) struct Heap {
+    size: u64,
+    used: u64,
+    allocated: u128,
+    deallocated: u128,
+}
+
+impl Heap {
+    pub(crate) fn new(size: u64) -> Self {
+        Heap {
+            size,
+            used: 0,
+            allocated: 0,
+            deallocated: 0,
+        }
+    }
+
+    pub(crate) fn size(&mut self) -> u64 {
+        self.size
+    }
+
+    pub(crate) fn alloc(&mut self, size: u64) {
+        self.used += size;
+        self.allocated += u128::from(size);
+    }
+
+    pub(crate) fn dealloc(&mut self, size: u64) {
+        self.used -= size;
+        self.deallocated += u128::from(size);
+    }
+}