HLSL: Support {...} initializer lists that are too short.

Test/hlsl.partialInit.frag

@@ -0,0 +1,22 @@
+struct outs {
+    int a;
+    float b;
+    bool c;
+    float4 v;
+};
+
+static float4 gv = {0,0,1};
+static float gfa[3] = {0,0};
+
+outs PixelShaderFunction(float4 input) : COLOR0
+{
+    outs o2 = { 3 };
+    outs o4;
+    o4.v = gv * gfa[2];
+    outs o1 = { };
+//    outs o3 = (outs)0;
+//    o4 = (outs)0;
+    o4.c = o1.c;
+
+    return o4;
+}