natvis support in build system + some natvis

Natvis/String.natvis

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+    <Type Name="String8">
+        <DisplayString Condition="Str == 0 || Size == 0">&lt;empty&gt;</DisplayString>
+        <DisplayString>{Str,[Size]s8}</DisplayString>
+        <StringView>Str,[Size]s8</StringView>
+        <Expand>
+            <Item Name="[size]">Size</Item>
+            <ArrayItems>
+                <Size>Size</Size>
+                <ValuePointer>Str</ValuePointer>
+            </ArrayItems>
+        </Expand>
+    </Type>
+
+    <Type Name="String16">
+        <DisplayString Condition="Str == 0 || Size == 0">&lt;empty&gt;</DisplayString>
+        <DisplayString>{Str,[Size]su}</DisplayString>
+        <StringView>Str,[Size]su</StringView>
+        <Expand>
+            <Item Name="[size]">Size</Item>
+            <ArrayItems>
+                <Size>Size</Size>
+                <ValuePointer>Str</ValuePointer>
+            </ArrayItems>
+        </Expand>
+    </Type>
+
+    <Type Name="StringBuffer">
+        <DisplayString Condition="Str == 0 || Size == 0">&lt;empty&gt; (capacity={Capacity})</DisplayString>
+        <DisplayString>{Str,[Size]s8} (capacity={Capacity})</DisplayString>
+        <StringView>Str,[Size]s8</StringView>
+        <Expand>
+            <Item Name="[size]">Size</Item>
+            <Item Name="[capacity]">Capacity</Item>
+            <ArrayItems>
+                <Size>Size</Size>
+                <ValuePointer>Str</ValuePointer>
+            </ArrayItems>
+        </Expand>
+    </Type>
+</AutoVisualizer>