Support multiple swizzled out operands

Swizzled out operands were added in bbbd9a2. This was sufficient
for most tests, but we ran into problems with umulExtended and
imulExtended, which have two.

This CL converts the tracking values to vectors so multiple operands
can be supported.

Test: KHR-GLES31.core.shader_bitfield_operation.*

SPIRV/GlslangToSpv.cpp

@@ -2353,10 +2353,10 @@ bool TGlslangToSpvTraverser::visitAggregate(glslang::TVisit visit, glslang::TInt
         spec_constant_op_mode_setter.turnOnSpecConstantOpMode();
 
     spv::Id result = spv::NoResult;
-    spv::Id invertedType = spv::NoType;       // to use to override the natural type of the node
-    spv::Builder::AccessChain complexLvalue;  // for holding swizzling l-values too complex for SPIR-V,
-                                              // for at out parameter
-    spv::Id temporaryLvalue = spv::NoResult;  // temporary to pass, as proxy for complexLValue
+    spv::Id invertedType = spv::NoType;                     // to use to override the natural type of the node
+    std::vector<spv::Builder::AccessChain> complexLvalues;  // for holding swizzling l-values too complex for
+                                                            // SPIR-V, for an out parameter
+    std::vector<spv::Id> temporaryLvalues;                  // temporaries to pass, as proxies for complexLValues
 
     auto resultType = [&invertedType, &node, this](){ return invertedType != spv::NoType ?
         invertedType :
@@ -2972,10 +2972,10 @@ bool TGlslangToSpvTraverser::visitAggregate(glslang::TVisit visit, glslang::TInt
                 // reduce to a simple access chain.  So, we need a temporary vector to
                 // receive the result, and must later swizzle that into the original
                 // l-value.
-                complexLvalue = builder.getAccessChain();
-                temporaryLvalue = builder.createVariable(spv::StorageClassFunction,
-                    builder.accessChainGetInferredType(), "swizzleTemp");
-                operands.push_back(temporaryLvalue);
+                complexLvalues.push_back(builder.getAccessChain());
+                temporaryLvalues.push_back(builder.createVariable(spv::StorageClassFunction,
+                    builder.accessChainGetInferredType(), "swizzleTemp"));
+                operands.push_back(temporaryLvalues.back());
             } else {
                 operands.push_back(builder.accessChainGetLValue());
             }
@@ -3072,9 +3072,11 @@ bool TGlslangToSpvTraverser::visitAggregate(glslang::TVisit visit, glslang::TInt
         }
         if (invertedType != spv::NoResult)
             result = createInvertedSwizzle(precision, *glslangOperands[0]->getAsBinaryNode(), result);
-        else if (temporaryLvalue != spv::NoResult) {
-            builder.setAccessChain(complexLvalue);
-            builder.accessChainStore(builder.createLoad(temporaryLvalue));
+        else if (!temporaryLvalues.empty()) {
+            for (unsigned int i = 0; i < temporaryLvalues.size(); ++i) {
+                builder.setAccessChain(complexLvalues[i]);
+                builder.accessChainStore(builder.createLoad(temporaryLvalues[i]));
+            }
         }
     }