Replace BitUtils with C++20: Counting Zeroes

With the upgrade to C++20, std::countl_zero and std::countr_zero can replace these home-spun implementations from the BitUtil.h library.

Source/Core/Core/PowerPC/Interpreter/Interpreter_Integer.cpp

@@ -209,7 +209,7 @@ void Interpreter::cmpl(UGeckoInstruction inst)
 
 void Interpreter::cntlzwx(UGeckoInstruction inst)
 {
-  rGPR[inst.RA] = u32(Common::CountLeadingZeros(rGPR[inst.RS]));
+  rGPR[inst.RA] = u32(std::countl_zero(rGPR[inst.RS]));
 
   if (inst.Rc)
     Helper_UpdateCR0(rGPR[inst.RA]);

Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp

@@ -2660,7 +2660,7 @@ void Jit64::cntlzwx(UGeckoInstruction inst)
 
   if (gpr.IsImm(s))
   {
-    gpr.SetImmediate32(a, Common::CountLeadingZeros(gpr.Imm32(s)));
+    gpr.SetImmediate32(a, static_cast<u32>(std::countl_zero(gpr.Imm32(s))));
   }
   else
   {

Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp

@@ -528,7 +528,7 @@ void JitArm64::cntlzwx(UGeckoInstruction inst)
 
   if (gpr.IsImm(s))
   {
-    gpr.SetImmediate(a, Common::CountLeadingZeros(gpr.GetImm(s)));
+    gpr.SetImmediate(a, static_cast<u32>(std::countl_zero(gpr.GetImm(s))));
     if (inst.Rc)
       ComputeRC0(gpr.GetImm(a));
   }