r600/sfn: make pin_dest_to_chan a virtual function

To simplify the scheduling we need the method to be callable for all
instruction types.

v2: remove now useless override in ExportInstr

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37096>

src/gallium/drivers/r600/sfn/sfn_instr.h

@@ -127,6 +127,8 @@ public:
 
    virtual AluGroup *as_alu_group() { return nullptr;}
 
+   virtual void pin_dest_to_chan() {}
+
 protected:
 
 
@@ -338,7 +340,7 @@ public:
 
    void update_indirect_addr(PRegister old_reg, PRegister addr) override;
 
-   void pin_dest_to_chan();
+   void pin_dest_to_chan() override;
 
 protected:
    InstrWithVectorResult(const InstrWithVectorResult& orig);

src/gallium/drivers/r600/sfn/sfn_instr_alu.h

@@ -102,7 +102,7 @@ public:
 
    int dest_chan() const { return m_dest ? m_dest->chan() : m_fallback_chan; }
 
-   void pin_dest_to_chan();
+   void pin_dest_to_chan() override;
 
    const VirtualValue *psrc(unsigned i) const { return i < m_src.size() ? m_src[i] : nullptr; }
    PVirtualValue psrc(unsigned i) { return i < m_src.size() ? m_src[i] : nullptr; }

src/gallium/drivers/r600/sfn/sfn_instr_export.h

@@ -228,8 +228,6 @@ public:
 
    uint8_t allowed_src_chan_mask() const override;
 
-   void pin_dest_to_chan() {}
-
 private:
    bool do_ready() const override;
    void do_print(std::ostream& os) const override;

src/gallium/drivers/r600/sfn/sfn_instr_mem.h

@@ -41,8 +41,6 @@ public:
 
    void update_indirect_addr(PRegister old_reg, PRegister addr) override;
 
-   void pin_dest_to_chan() {}
-
 private:
    static bool emit_atomic_read(nir_intrinsic_instr *intr, Shader& shader);
    static bool emit_atomic_op2(nir_intrinsic_instr *intr, Shader& shader);