shader: remove IR opcodes and IREmitter helpers that nothing produces

src/graphics/shader/recompiler/ir/IREmitter.h

@@ -12,8 +12,6 @@ class IREmitter {
 public:
 	explicit IREmitter(Block* block);
 
-	void SetBlock(Block* block);
-
 	Value Emit(ValueOpcode opcode, std::initializer_list<Value> args = {}, uint64_t flags = 0);
 
 	template <typename T>
@@ -54,8 +52,6 @@ public:
 
 	F32 BitCastF32(U32 value);
 	U32 BitCastU32(F32 value);
-	F16 BitCastF16(U32 value);
-	U32 BitCastU32(F16 value);
 	U64 ConstructU64(U32 low, U32 high);
 	U32 CompositeExtract(Value composite, uint32_t index);