X86: Elide use of RegClassByHwMode in some ptr_rc_tailcall uses (llvm#159874)

Different instructions are used for the 32-bit and 64-bit cases
anyway, so directly use the concrete register class in the
instruction.

Author: arsenm

llvm/lib/Target/X86/X86InstrCompiler.td

@@ -1324,8 +1324,8 @@ def : Pat<(X86imp_call (i64 tglobaladdr:$dst)),
 // %r11. This happens when calling a vararg function with 6 arguments.
 //
 // Match an X86tcret that uses less than 7 volatile registers.
-def : Pat<(X86tcret ptr_rc_tailcall:$dst, timm:$off),
-          (TCRETURNri ptr_rc_tailcall:$dst, timm:$off)>,
+def : Pat<(X86tcret GR32_TC:$dst, timm:$off),
+          (TCRETURNri GR32_TC:$dst, timm:$off)>,
           Requires<[Not64BitMode, IsNotHiPECCFunc, NotUseIndirectThunkCalls]>;
 
 def : Pat<(X86tcret GR32:$dst, timm:$off),

llvm/lib/Target/X86/X86InstrControl.td

@@ -280,7 +280,7 @@ let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1,
     isCodeGenOnly = 1, Uses = [ESP, SSP] in {
   def TCRETURNdi : PseudoI<(outs), (ins i32imm_brtarget:$dst, i32imm:$offset),
                            []>, Sched<[WriteJump]>;
-  def TCRETURNri : PseudoI<(outs), (ins ptr_rc_tailcall:$dst, i32imm:$offset),
+  def TCRETURNri : PseudoI<(outs), (ins GR32_TC:$dst, i32imm:$offset),
                            []>, Sched<[WriteJump]>;
 
   def TCRETURN_HIPE32ri : PseudoI<(outs), (ins GR32:$dst, i32imm:$offset),
@@ -359,7 +359,7 @@ let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1,
                                (ins i64i32imm_brtarget:$dst, i32imm:$offset),
                                []>, Sched<[WriteJump]>;
   def TCRETURNri64   : PseudoI<(outs),
-                               (ins ptr_rc_tailcall:$dst, i32imm:$offset),
+                               (ins GR64_TC:$dst, i32imm:$offset),
                                []>, Sched<[WriteJump]>;
   def TCRETURN_WIN64ri : PseudoI<(outs), (ins GR64_TCW64:$dst, i32imm:$offset),
                                 []>, Sched<[WriteJump]>;