Build: Fix some warnings.
diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 10ad425..3a36b38 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -5706,7 +5706,7 @@
         spv::IdImmediate scope = { true, builder.makeUintConstant(spv::ScopeSubgroup) };
         spvGroupOperands.push_back(scope);
         if (groupOperation != spv::GroupOperationMax) {
-            spv::IdImmediate groupOp = { false, groupOperation };
+            spv::IdImmediate groupOp = { false, (unsigned)groupOperation };
             spvGroupOperands.push_back(groupOp);
         }
 #endif
@@ -5903,7 +5903,7 @@
         } else {
             spv::IdImmediate scope = { true, builder.makeUintConstant(spv::ScopeSubgroup) };
             spvGroupOperands.push_back(scope);
-            spv::IdImmediate groupOp = { false, groupOperation };
+            spv::IdImmediate groupOp = { false, (unsigned)groupOperation };
             spvGroupOperands.push_back(groupOp);
             spvGroupOperands.push_back(scalar);
         }
@@ -6249,7 +6249,7 @@
 
     // Next, for all operations that use a Group Operation, push that as an operand.
     if (groupOperation != spv::GroupOperationMax) {
-        spv::IdImmediate groupOperand = { false, groupOperation };
+        spv::IdImmediate groupOperand = { false, (unsigned)groupOperation };
         spvGroupOperands.push_back(groupOperand);
     }