[PowerPC] Support @tls in the asm parser

This adds support for the last missing construct to parse TLS-related
assembler code:
   add 3, 4, symbol@tls

The ADD8TLS currently hard-codes the @tls into the assembler string.
This cannot be handled by the asm parser, since @tls is parsed as
a symbol variant.  This patch changes ADD8TLS to have the @tls suffix
printed as symbol variant on output too, which allows us to remove
the isCodeGenOnly marker from ADD8TLS.  This in turn means that we
can add a AsmOperand to accept @tls marked symbols on input.

As a side effect, this means that the fixup_ppc_tlsreg fixup type
is no longer necessary and can be merged into fixup_ppc_nofixup.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185692 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCMCInstLower.cpp b/lib/Target/PowerPC/PPCMCInstLower.cpp
index 1eefb7f..b7e88d4 100644
--- a/lib/Target/PowerPC/PPCMCInstLower.cpp
+++ b/lib/Target/PowerPC/PPCMCInstLower.cpp
@@ -127,6 +127,9 @@
     case PPCII::MO_TOC_LO:
       RefKind = MCSymbolRefExpr::VK_PPC_TOC_LO;
       break;
+    case PPCII::MO_TLS:
+      RefKind = MCSymbolRefExpr::VK_PPC_TLS;
+      break;
   }
 
   const MCExpr *Expr = MCSymbolRefExpr::Create(Symbol, RefKind, Ctx);