Add end-to-end corpus from Tint SPIR-V Reader

Add the unit tests samples from src/reader/spirv when:
- they are valid for Vulkan 1.0 (plus some common extensions)
- they should translate to valid WGSL

Bug: tint:1043
Change-Id: I40a01990dbc40aff5cf7ace0b1aabfd0e437f638
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/60000
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: David Neto <dneto@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: James Price <jrprice@google.com>
diff --git a/test/unittest/reader/spirv/SpvParserFunctionVarTest_EmitFunctionVariables_ArrayInitializer_Null.spvasm b/test/unittest/reader/spirv/SpvParserFunctionVarTest_EmitFunctionVariables_ArrayInitializer_Null.spvasm
new file mode 100644
index 0000000..3461475
--- /dev/null
+++ b/test/unittest/reader/spirv/SpvParserFunctionVarTest_EmitFunctionVariables_ArrayInitializer_Null.spvasm
@@ -0,0 +1,49 @@
+; Test: SpvParserFunctionVarTest_EmitFunctionVariables_ArrayInitializer_Null.spvasm
+; SPIR-V
+; Version: 1.0
+; Generator: Khronos SPIR-V Tools Assembler; 0
+; Bound: 201
+; Schema: 0
+OpCapability Shader
+OpMemoryModel Logical Simple
+OpEntryPoint Fragment %100 "main"
+OpExecutionMode %100 OriginUpperLeft
+%void = OpTypeVoid
+%2 = OpTypeFunction %void
+%bool = OpTypeBool
+%float = OpTypeFloat 32
+%uint = OpTypeInt 32 0
+%int = OpTypeInt 32 1
+%_ptr_Function_bool = OpTypePointer Function %bool
+%_ptr_Function_float = OpTypePointer Function %float
+%_ptr_Function_uint = OpTypePointer Function %uint
+%_ptr_Function_int = OpTypePointer Function %int
+%true = OpConstantTrue %bool
+%false = OpConstantFalse %bool
+%float_0 = OpConstant %float 0
+%float_1_5 = OpConstant %float 1.5
+%uint_0 = OpConstant %uint 0
+%uint_1 = OpConstant %uint 1
+%int_n1 = OpConstant %int -1
+%int_0 = OpConstant %int 0
+%int_1 = OpConstant %int 1
+%int_3 = OpConstant %int 3
+%uint_2 = OpConstant %uint 2
+%uint_3 = OpConstant %uint 3
+%uint_4 = OpConstant %uint 4
+%uint_5 = OpConstant %uint 5
+%v2int = OpTypeVector %int 2
+%v2float = OpTypeVector %float 2
+%mat3v2float = OpTypeMatrix %v2float 3
+%28 = OpConstantNull %v2int
+%_arr_uint_uint_2 = OpTypeArray %uint %uint_2
+%_struct_30 = OpTypeStruct %uint %float %_arr_uint_uint_2
+%_ptr_Function__arr_uint_uint_2 = OpTypePointer Function %_arr_uint_uint_2
+%uint_2_0 = OpConstant %uint 2
+%33 = OpConstantNull %_arr_uint_uint_2
+%100 = OpFunction %void None %2
+%34 = OpLabel
+%200 = OpVariable %_ptr_Function__arr_uint_uint_2 Function %33
+OpReturn
+OpFunctionEnd
+