Add custom glslang feature to allow specifying I/O automap base location

renderdoc/3rdparty/glslang/glslang/MachineIndependent/ShaderLang.cpp

@@ -1859,6 +1859,10 @@ void TShader::setUniformLocationBase(int base)
 {
     intermediate->setUniformLocationBase(base);
 }
+void TShader::setIOLocationBase(int base)
+{
+    intermediate->setIOLocationBase(base);
+}
 void TShader::setBindingsPerResourceType() { intermediate->setBindingsPerResourceType(); }
 void TShader::setNoStorageFormat(bool useUnknownFormat) { intermediate->setNoStorageFormat(useUnknownFormat); }
 void TShader::setResourceSetBinding(const std::vector<std::string>& base)   { intermediate->setResourceSetBinding(base); }

renderdoc/3rdparty/glslang/glslang/MachineIndependent/iomapper.cpp

@@ -866,8 +866,8 @@ private:
 TDefaultIoResolverBase::TDefaultIoResolverBase(const TIntermediate& intermediate)
     : referenceIntermediate(intermediate)
     , nextUniformLocation(intermediate.getUniformLocationBase())
-    , nextInputLocation(0)
-    , nextOutputLocation(0)
+    , nextInputLocation(intermediate.getIOLocationBase())
+    , nextOutputLocation(intermediate.getIOLocationBase())
 {
     memset(stageMask, false, sizeof(bool) * (EShLangCount + 1));
     memset(stageIntermediates, 0, sizeof(TIntermediate*) * (EShLangCount));

renderdoc/3rdparty/glslang/glslang/MachineIndependent/localintermediate.h

@@ -362,6 +362,7 @@ public:
         spirvRequirement(nullptr),
         spirvExecutionMode(nullptr),
         uniformLocationBase(0),
+        ioLocationBase(0),
         quadDerivMode(false), reqFullQuadsMode(false)
     {
         localSize[0] = 1;
@@ -1019,6 +1020,9 @@ public:
 
     void setUniformLocationBase(int base) { uniformLocationBase = base; }
     int getUniformLocationBase() const { return uniformLocationBase; }
+    
+    void setIOLocationBase(int base) { ioLocationBase = base; }
+    int getIOLocationBase() const { return ioLocationBase; }
 
     void setNeedsLegalization() { needToLegalize = true; }
     bool needsLegalization() const { return needToLegalize; }
@@ -1331,6 +1335,7 @@ protected:
     std::map<TString, AstRefType> bindlessImageModeCaller;
     std::unordered_map<std::string, int> uniformLocationOverrides;
     int uniformLocationBase;
+    int ioLocationBase;
     bool quadDerivMode;
     bool reqFullQuadsMode;
     TNumericFeatures numericFeatures;

renderdoc/3rdparty/glslang/glslang/Public/ShaderLang.h

@@ -499,6 +499,7 @@ public:
     void setBindingsPerResourceType();
     void addUniformLocationOverride(const char* name, int loc);
     void setUniformLocationBase(int base);
+    void setIOLocationBase(int base);
     void setInvertY(bool invert);
     void setDxPositionW(bool dxPosW);
     void setEnhancedMsgs();