fixup: initialize globals in test

Author: bogner

llvm/test/CodeGen/DirectX/Metadata/cbuffer_metadata.ll

@@ -6,13 +6,13 @@ target datalayout = "e-m:e-p:32:32-i1:32-i8:8-i16:16-i32:32-i64:64-f16:16-f32:32
 target triple = "dxil-pc-shadermodel6.6-compute"
 
 %__cblayout_CB1 = type <{ float, i32, double, <2 x i32> }>
-@CB1.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CB1, 24, 0, 4, 8, 16))
+@CB1.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CB1, 24, 0, 4, 8, 16)) poison
 
 %__cblayout_CB2 = type <{ float, double, float, half, i16, i64, i32 }>
-@CB2.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CB2, 36, 0, 8, 16, 20, 22, 24, 32))
+@CB2.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CB2, 36, 0, 8, 16, 20, 22, 24, 32)) poison
 
 %__cblayout_CB3 = type <{ double, <3 x float>, float, <3 x double>, half, <2 x double>, float, <3 x half>, <3 x half> }>
-@CB3.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CB3, 96, 0, 16, 28, 32, 56, 64, 80, 84, 90))
+@CB3.cb = global target("dx.CBuffer", target("dx.Layout", %__cblayout_CB3, 96, 0, 16, 28, 32, 56, 64, 80, 84, 90)) poison
 
 ; PRINT:; Resource Bindings:
 ; PRINT-NEXT:;