SpirvShader: Fix ASSERT firing in debugger

https://swiftshader-review.googlesource.com/c/SwiftShader/+/43693 added an assert to SpirvShader::Operand that checks the object is a constant or an intermediate.

SpirvShader::Impl::Debugger::exposeVariable() was constructing an Operand for pointer object types (but was not using it), firing this assert.

Bug: b/129000021
Bug: b/148401179
Change-Id: Id22a92e28b1bb16781b98979d26180b1c022db96
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/44014
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Ben Clayton <bclayton@google.com>

src/Pipeline/SpirvShaderDebugger.cpp

diff --git a/src/Pipeline/SpirvShaderDebugger.cpp b/src/Pipeline/SpirvShaderDebugger.cpp
index be57e54..214ef1c 100644
--- a/src/Pipeline/SpirvShaderDebugger.cpp
+++ b/src/Pipeline/SpirvShaderDebugger.cpp
@@ -1288,21 +1288,23 @@
 	}
 
 	// No debug type information. Derive from SPIR-V.
-	Operand val(shader, state, id);
 	switch(shader->getType(obj).opcode())
 	{
 		case spv::OpTypeInt:
 		{
+			Operand val(shader, state, id);
 			group.put<Key, int>(key, Extract(val.Int(0), l));
 		}
 		break;
 		case spv::OpTypeFloat:
 		{
+			Operand val(shader, state, id);
 			group.put<Key, float>(key, Extract(val.Float(0), l));
 		}
 		break;
 		case spv::OpTypeVector:
 		{
+			Operand val(shader, state, id);
 			auto count = shader->getType(obj).definition.word(3);
 			switch(count)
 			{