Assert on Subzero translation errors.

Bug swiftshader:6

Change-Id: I7d32d12081f4a704f4731cfa29c0eadf75a43d49
Reviewed-on: https://swiftshader-review.googlesource.com/7738
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-on: https://swiftshader-review.googlesource.com/8130
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/Reactor/SubzeroReactor.cpp

diff --git a/src/Reactor/SubzeroReactor.cpp b/src/Reactor/SubzeroReactor.cpp
index f7b0e32..650fc94 100644
--- a/src/Reactor/SubzeroReactor.cpp
+++ b/src/Reactor/SubzeroReactor.cpp
@@ -411,6 +411,8 @@
 		::function->setFunctionName(Ice::GlobalString::createWithString(::context, asciiName));
 
 		::function->translate();
+		assert(!::function->hasError());
+
 		auto *globals = ::function->getGlobalInits().release();
 
 		if(globals && !globals->empty())