nv50/ir: resolve -Woverloaded-virtual=1 warnings

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23656>

src/nouveau/codegen/nv50_ir.h

@@ -1399,15 +1399,15 @@ public:
    bool run(Function *, bool ordered = false, bool skipPhi = false);
 
 private:
+   bool doRun(Program *, bool ordered, bool skipPhi);
+   bool doRun(Function *, bool ordered, bool skipPhi);
+
+protected:
    // return false to continue with next entity on next higher level
    virtual bool visit(Function *) { return true; }
    virtual bool visit(BasicBlock *) { return true; }
    virtual bool visit(Instruction *) { return false; }
 
-   bool doRun(Program *, bool ordered, bool skipPhi);
-   bool doRun(Function *, bool ordered, bool skipPhi);
-
-protected:
    bool err;
    Function *func;
    Program *prog;

src/nouveau/codegen/nv50_ir_lowering_gm107.h

@@ -6,7 +6,8 @@ class GM107LoweringPass : public NVC0LoweringPass
 {
 public:
    GM107LoweringPass(Program *p) : NVC0LoweringPass(p) {}
-private:
+protected:
+   using NVC0LoweringPass::visit;
    bool visit(Instruction *) override;
 
    bool handleManualTXD(TexInstruction *) override;
@@ -18,10 +19,10 @@ private:
 
 class GM107LegalizeSSA : public NVC0LegalizeSSA
 {
-private:
+protected:
+   using NVC0LegalizeSSA::visit;
    bool visit(Instruction *) override;
 
-protected:
    void handlePFETCH(Instruction *);
    void handleLOAD(Instruction *);
    void handleQUADON(Instruction *);

src/nouveau/codegen/nv50_ir_lowering_nvc0.h

@@ -56,7 +56,8 @@ namespace nv50_ir {
 
 class NVC0LegalizeSSA : public Pass
 {
-private:
+protected:
+   using Pass::visit;
    bool visit(BasicBlock *) override;
    bool visit(Function *) override;
 
@@ -69,7 +70,6 @@ private:
    void handleShift(Instruction *);
    void handleBREV(Instruction *);
 
-protected:
    void handleFTZ(Instruction *);
 
    BuildUtil bld;
@@ -80,10 +80,12 @@ class NVC0LegalizePostRA : public Pass
 public:
    NVC0LegalizePostRA(const Program *);
 
-private:
+protected:
+   using Pass::visit;
    bool visit(Function *) override;
    bool visit(BasicBlock *) override;
 
+private:
    void replaceCvt(Instruction *);
    void replaceZero(Instruction *);
    bool tryReplaceContWithBra(BasicBlock *);
@@ -156,11 +158,10 @@ protected:
    Value *loadMsAdjInfo32(TexInstruction::Target targ, uint32_t index, int slot, Value *ind, bool bindless);
 
    bool visit(Instruction *) override;
-
-private:
    bool visit(Function *) override;
    bool visit(BasicBlock *) override;
 
+private:
    void readTessCoord(LValue *dst, int c);
 
    Value *loadResInfo32(Value *ptr, uint32_t off, uint16_t base);