[PowerPC] Support @higher et.al. modifiers

This adds support for the @higher, @highera, @highest, and @highesta
modifers, including some missing relocation types.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184550 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index 454965a..17da679 100644
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -199,6 +199,10 @@
   case VK_PPC_LO: return "l";
   case VK_PPC_HI: return "h";
   case VK_PPC_HA: return "ha";
+  case VK_PPC_HIGHER: return "higher";
+  case VK_PPC_HIGHERA: return "highera";
+  case VK_PPC_HIGHEST: return "highest";
+  case VK_PPC_HIGHESTA: return "highesta";
   case VK_PPC_TOCBASE: return "tocbase";
   case VK_PPC_TOC: return "toc";
   case VK_PPC_TOC_LO: return "toc@l";
@@ -287,6 +291,14 @@
     .Case("h", VK_PPC_HI)
     .Case("HA", VK_PPC_HA)
     .Case("ha", VK_PPC_HA)
+    .Case("HIGHER", VK_PPC_HIGHER)
+    .Case("higher", VK_PPC_HIGHER)
+    .Case("HIGHERA", VK_PPC_HIGHERA)
+    .Case("highera", VK_PPC_HIGHERA)
+    .Case("HIGHEST", VK_PPC_HIGHEST)
+    .Case("highest", VK_PPC_HIGHEST)
+    .Case("HIGHESTA", VK_PPC_HIGHESTA)
+    .Case("highesta", VK_PPC_HIGHESTA)
     .Case("TOCBASE", VK_PPC_TOCBASE)
     .Case("tocbase", VK_PPC_TOCBASE)
     .Case("TOC", VK_PPC_TOC)