spirv-reader: set failure bit when SPIR-V validation fails

The error message was already being logged, but the status
flag was not being set.

Change-Id: I7f6f2f45c15a64dd089e221c62218afe9e774edd
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/49643
Commit-Queue: David Neto <dneto@google.com>
Auto-Submit: David Neto <dneto@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>

src/reader/spirv/parser_impl.cc

@@ -291,6 +291,7 @@ bool ParserImpl::Parse() {
   // Only consider modules valid for Vulkan 1.0.  On failure, the message
   // consumer will set the error status.
   if (!spv_tools.Validate(spv_binary_)) {
+    success_ = false;
     return false;
   }
   if (!BuildInternalModule()) {

src/reader/spirv/parser_impl_module_var_test.cc

@@ -2184,13 +2184,13 @@ TEST_F(SpvModuleScopeVarParserTest, SampleId_I32_FunctParam) {
     OpFunctionEnd
  )";
   auto p = parser(test::Assemble(assembly));
-  // TODO(dneto): We can handle this if we make a shadow variable and mutate
-  // the parameter type.
-  ASSERT_FALSE(p->BuildAndParseInternalModule());
-  EXPECT_THAT(
-      p->error(),
-      HasSubstr(
-          "unhandled use of a pointer to the SampleId builtin, with ID: 1"));
+
+  // This example is invalid because you can't pass pointer-to-Input
+  // as a function parameter.
+  EXPECT_FALSE(p->Parse());
+  EXPECT_FALSE(p->success());
+  EXPECT_THAT(p->error(),
+              HasSubstr("Invalid storage class for pointer operand 1"));
 }
 
 TEST_F(SpvModuleScopeVarParserTest, SampleId_U32_Load_Direct) {

src/reader/spirv/parser_impl_test_helper.h

@@ -64,6 +64,7 @@ class ParserImplWrapperForTest {
   Namer& namer() { return impl_.namer(); }
   ProgramBuilder& builder() { return impl_.builder(); }
   const std::string error() { return impl_.error(); }
+  bool success() { return impl_.success(); }
   FailStream& Fail() { return impl_.Fail(); }
   spvtools::opt::IRContext* ir_context() { return impl_.ir_context(); }