Just make computeTypeLocationSize const.

glslang/MachineIndependent/linkValidate.cpp

@@ -646,7 +646,7 @@ int TIntermediate::addUsedLocation(const TQualifier& qualifier, const TType& typ
 
 // Recursively figure out how many locations are used up by an input or output type.
 // Return the size of type, as measured by "locations".
-int TIntermediate::computeTypeLocationSize(const TType& type)
+int TIntermediate::computeTypeLocationSize(const TType& type) const
 {
     // "If the declared input is an array of size n and each element takes m locations, it will be assigned m * n 
     // consecutive locations..."

glslang/MachineIndependent/localintermediate.h

@@ -234,7 +234,7 @@ public:
     bool inIoAccessed(const TString& name) const { return ioAccessed.find(name) != ioAccessed.end(); }
 
     int addUsedLocation(const TQualifier&, const TType&, bool& typeCollision);
-    int computeTypeLocationSize(const TType&);
+    int computeTypeLocationSize(const TType&) const;
 
     bool setXfbBufferStride(int buffer, int stride)
     {