Externals: Update glslang.

This updates glslang to commit 9bb8cfffb0eed010e07132282c41d73064a7a609
which is the current version listed in the known_good.json file for the
version 1.3.212 of the Vulkan-ValidationLayers repo.

Externals/glslang/SPIRV/SPVRemapper.cpp

@@ -297,15 +297,21 @@ namespace spv {
     std::string spirvbin_t::literalString(unsigned word) const
     {
         std::string literal;
+        const spirword_t * pos = spv.data() + word;
 
         literal.reserve(16);
 
-        const char* bytes = reinterpret_cast<const char*>(spv.data() + word);
-
-        while (bytes && *bytes)
-            literal += *bytes++;
-
-        return literal;
+        do {
+            spirword_t word = *pos;
+            for (int i = 0; i < 4; i++) {
+                char c = word & 0xff;
+                if (c == '\0')
+                    return literal;
+                literal += c;
+                word >>= 8;
+            }
+            pos++;
+        } while (true);
     }
 
     void spirvbin_t::applyMap()
@@ -544,6 +550,9 @@ namespace spv {
         // Extended instructions: currently, assume everything is an ID.
         // TODO: add whatever data we need for exceptions to that
         if (opCode == spv::OpExtInst) {
+
+            idFn(asId(word)); // Instruction set is an ID that also needs to be mapped
+
             word        += 2; // instruction set, and instruction from set
             numOperands -= 2;
 
@@ -625,6 +634,9 @@ namespace spv {
                 break;
             }
 
+            case spv::OperandVariableLiteralStrings:
+                return nextInst;
+
             // Execution mode might have extra literal operands.  Skip them.
             case spv::OperandExecutionMode:
                 return nextInst;
@@ -827,7 +839,15 @@ namespace spv {
             [&](spv::Id& id) {
                 if (thisOpCode != spv::OpNop) {
                     ++idCounter;
-                    const std::uint32_t hashval = opCounter[thisOpCode] * thisOpCode * 50047 + idCounter + fnId * 117;
+                    const std::uint32_t hashval =
+                        // Explicitly cast operands to unsigned int to avoid integer
+                        // promotion to signed int followed by integer overflow,
+                        // which would result in undefined behavior.
+                        static_cast<unsigned int>(opCounter[thisOpCode])
+                        * thisOpCode
+                        * 50047
+                        + idCounter
+                        + static_cast<unsigned int>(fnId) * 117;
 
                     if (isOldIdUnmapped(id))
                         localId(id, nextUnusedId(hashval % softTypeIdLimit + firstMappedID));