Update SPIRV libraries (#99)

* Update SPIRV libraries

- Update `spirv-cross`
- Update `spirv-tools`
- Update `glslang`

`spirv-tools` contains a fix for an issue we reported (unnecessary promotions to highp in certain expressions).

* Add SPIRV-Tools dependency to matinfo

third_party/spirv-tools/test/text_to_binary.function_test.cpp

@@ -15,10 +15,12 @@
 // Assembler tests for instructions in the "Function" section of the
 // SPIR-V spec.
 
-#include "unit_spirv.h"
+#include <string>
+#include <vector>
 
 #include "gmock/gmock.h"
-#include "test_fixture.h"
+#include "test/test_fixture.h"
+#include "test/unit_spirv.h"
 
 namespace spvtools {
 namespace {