Allow reinterpreting formats of constant blocks that have bytes backing

* Even without a true buffer, as long as we have access to the bag of bytes and
  a non-opaque layout we can allow reinterpreting.

renderdoc/api/replay/shader_types.h

@@ -1109,7 +1109,7 @@ struct ConstantBlock
   {
     return name == o.name && variables == o.variables && bindPoint == o.bindPoint &&
            byteSize == o.byteSize && bufferBacked == o.bufferBacked &&
-           compileConstants == o.compileConstants;
+           inlineDataBytes == o.inlineDataBytes && compileConstants == o.compileConstants;
   }
   bool operator<(const ConstantBlock &o) const
   {
@@ -1123,6 +1123,8 @@ struct ConstantBlock
       return byteSize < o.byteSize;
     if(!(bufferBacked == o.bufferBacked))
       return bufferBacked < o.bufferBacked;
+    if(!(inlineDataBytes == o.inlineDataBytes))
+      return inlineDataBytes < o.inlineDataBytes;
     if(!(compileConstants == o.compileConstants))
       return compileConstants < o.compileConstants;
     return false;
@@ -1145,6 +1147,8 @@ some other API-specific method, such as direct function calls or they may be com
 specialisation constants.
 )");
   bool bufferBacked = true;
+  DOCUMENT("``True`` if this is backed by in-line data bytes rather than a specific buffer.");
+  bool inlineDataBytes = false;
   DOCUMENT("``True`` if this is a virtual buffer listing compile-time specialisation constants.");
   bool compileConstants = false;
 };

renderdoc/driver/shaders/spirv/spirv_reflect.cpp

@@ -1269,6 +1269,7 @@ void Reflector::MakeReflection(const GraphicsAPI sourceAPI, const ShaderStage st
             if(cblock.name.empty())
               cblock.name = StringFormat::Fmt("uniforms%u", global.id.value());
             cblock.bufferBacked = !pushConst;
+            cblock.inlineDataBytes = pushConst;
 
             MakeConstantBlockVariables(effectiveStorage, *varType, 0, 0, cblock.variables,
                                        pointerTypes, specInfo);
@@ -1319,6 +1320,7 @@ void Reflector::MakeReflection(const GraphicsAPI sourceAPI, const ShaderStage st
   {
     specblock.name = "Specialization Constants";
     specblock.bufferBacked = false;
+    specblock.inlineDataBytes = true;
     specblock.compileConstants = true;
     specblock.byteSize = 0;
 
@@ -1338,6 +1340,7 @@ void Reflector::MakeReflection(const GraphicsAPI sourceAPI, const ShaderStage st
   {
     globalsblock.name = "$Globals";
     globalsblock.bufferBacked = false;
+    globalsblock.inlineDataBytes = false;
     globalsblock.byteSize = (uint32_t)globalsblock.variables.size();
     globalsblock.bindPoint = (int)cblocks.size();