[PowerPC] Add DWARF numbers for CA (XER), etc.

For registers that have DWARF numbers (like CA, which is really part of XER),
add them. Also, RM is not an SPR, and the declaration hack (where it is
declared as an SPR with an arbitrary number) is not needed, so just declare it
as a register.

NFC; although CA's register number will be needed when stackmap/patchpoint
support is added.

llvm-svn: 225800

llvm/lib/Target/PowerPC/PPCRegisterInfo.td

@@ -131,8 +131,8 @@ foreach Index = 0-31 in {
 }
 
 // The reprsentation of r0 when treated as the constant 0.
-def ZERO  : GPR<0, "0">;
-def ZERO8 : GP8<ZERO, "0">;
+def ZERO  : GPR<0, "0">,    DwarfRegAlias<R0>;
+def ZERO8 : GP8<ZERO, "0">, DwarfRegAlias<X0>;
 
 // Representations of the frame pointer used by ISD::FRAMEADDR.
 def FP   : GPR<0 /* arbitrary */, "**FRAME POINTER**">;
@@ -203,7 +203,7 @@ def VRSAVE: SPR<256, "vrsave">, DwarfRegNum<[109]>;
 // Carry bit.  In the architecture this is really bit 0 of the XER register
 // (which really is SPR register 1);  this is the only bit interesting to a
 // compiler.
-def CARRY: SPR<1, "ca">;
+def CARRY: SPR<1, "ca">, DwarfRegNum<[76]>;
 
 // FP rounding mode:  bits 30 and 31 of the FP status and control register
 // This is not allocated as a normal register; it appears only in
@@ -212,8 +212,7 @@ def CARRY: SPR<1, "ca">;
 // most registers, it has to be done in code; to make this work all the
 // return and call instructions are described as Uses of RM, so instructions
 // that do nothing but change RM will not get deleted.
-// Also, in the architecture it is not really a SPR; 512 is arbitrary.
-def RM: SPR<512, "**ROUNDING MODE**">;
+def RM: PPCReg<"**ROUNDING MODE**">;
 
 /// Register classes
 // Allocate volatiles first