SPV: Use heuristic to avoid geometry multi-streams when possible.
diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 212d45b..5eb097b 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -1803,7 +1803,7 @@
             // Decorate the structure
             addDecoration(spvType, TranslateLayoutDecoration(type, qualifier.layoutMatrix));
             addDecoration(spvType, TranslateBlockDecoration(type));
-            if (type.getQualifier().hasStream()) {
+            if (type.getQualifier().hasStream() && glslangIntermediate->isMultiStream()) {
                 builder.addCapability(spv::CapabilityGeometryStreams);
                 builder.addDecoration(spvType, spv::DecorationStream, type.getQualifier().layoutStream);
             }
@@ -3599,7 +3599,7 @@
     }
 
     addDecoration(id, TranslateInvariantDecoration(symbol->getType().getQualifier()));
-    if (symbol->getQualifier().hasStream()) {
+    if (symbol->getQualifier().hasStream() && glslangIntermediate->isMultiStream()) {
         builder.addCapability(spv::CapabilityGeometryStreams);
         builder.addDecoration(id, spv::DecorationStream, symbol->getQualifier().layoutStream);
     }