Vendor dependencies

Let's see how I like this workflow.

vendor/smallvec/tests/debugger_visualizer.rs

@@ -0,0 +1,68 @@
+use debugger_test::debugger_test;
+use smallvec::{smallvec, SmallVec};
+
+#[inline(never)]
+fn __break() {}
+
+#[debugger_test(
+    debugger = "cdb",
+    commands = r#"
+.nvlist
+dx sv
+
+g
+
+dx sv
+
+g
+
+dx sv
+"#,
+    expected_statements = r#"
+sv               : { len=0x2 } [Type: smallvec::SmallVec<array$<i32,4> >]
+    [<Raw View>]     [Type: smallvec::SmallVec<array$<i32,4> >]
+    [capacity]       : 4
+    [len]            : 0x2 [Type: unsigned __int64]
+    [0]              : 1 [Type: int]
+    [1]              : 2 [Type: int]
+
+sv               : { len=0x5 } [Type: smallvec::SmallVec<array$<i32,4> >]
+    [<Raw View>]     [Type: smallvec::SmallVec<array$<i32,4> >]
+    [capacity]       : 0x8 [Type: unsigned __int64]
+    [len]            : 0x5 [Type: unsigned __int64]
+    [0]              : 5 [Type: int]
+    [1]              : 2 [Type: int]
+    [2]              : 3 [Type: int]
+    [3]              : 4 [Type: int]
+    [4]              : 5 [Type: int]
+
+sv               : { len=0x5 } [Type: smallvec::SmallVec<array$<i32,4> >]
+    [<Raw View>]     [Type: smallvec::SmallVec<array$<i32,4> >]
+    [capacity]       : 0x8 [Type: unsigned __int64]
+    [len]            : 0x5 [Type: unsigned __int64]
+    [0]              : 2 [Type: int]
+    [1]              : 3 [Type: int]
+    [2]              : 4 [Type: int]
+    [3]              : 5 [Type: int]
+    [4]              : 5 [Type: int]
+"#
+)]
+#[inline(never)]
+fn test_debugger_visualizer() {
+    // This SmallVec can hold up to 4 items on the stack:
+    let mut sv: SmallVec<[i32; 4]> = smallvec![1, 2];
+    __break();
+
+    // Overfill the SmallVec to move its contents to the heap
+    for i in 3..6 {
+        sv.push(i);
+    }
+
+    // Update the contents of the first value of the SmallVec.
+    sv[0] = sv[1] + sv[2];
+    __break();
+
+    // Sort the SmallVec in place.
+    sv.sort();
+    __break();
+}