Add 'invalid' as a Reference Kind so that unknown/invalid kind strings can return that fact to the caller for use in constructing an error message, rather that triggering an assertion.

llvm-svn: 158547
diff --git a/lld/lib/ReaderWriter/MachO/ReferenceKinds.cpp b/lld/lib/ReaderWriter/MachO/ReferenceKinds.cpp
index 75c9f1b..f6c2dc5 100644
--- a/lld/lib/ReaderWriter/MachO/ReferenceKinds.cpp
+++ b/lld/lib/ReaderWriter/MachO/ReferenceKinds.cpp
@@ -71,13 +71,16 @@
     .Case("lazyTarget",            lazyTarget)
     .Case("lazyImmediate",         lazyImmediate)
     .Case("subordinateFDE",        subordinateFDE)
-    .Case("subordinateLSDA",       subordinateLSDA);
+    .Case("subordinateLSDA",       subordinateLSDA)
+    .Default(invalid);
 
   llvm_unreachable("invalid x86_64 Reference kind");
 }
 
 StringRef KindHandler_x86_64::kindToString(Reference::Kind kind) {
   switch ( (Kinds)kind ) {
+    case invalid:
+      return StringRef("invalid");
     case none:
       return StringRef("none");
     case branch32: 
@@ -175,6 +178,9 @@
     case subordinateLSDA:
       // do nothing
       break;
+    case invalid:
+      assert(0 && "invalid Reference Kind");
+      break;
   }
 }
 
@@ -194,13 +200,16 @@
     .Case("funcRel32",             funcRel32)
     .Case("pointer32",             pointer32)
     .Case("lazyTarget",            lazyTarget)
-    .Case("lazyImmediate",         lazyImmediate);
+    .Case("lazyImmediate",         lazyImmediate)
+    .Default(invalid);
   
   llvm_unreachable("invalid x86 Reference kind");
 }
 
 StringRef KindHandler_x86::kindToString(Reference::Kind kind) {
   switch ( (Kinds)kind ) {
+    case invalid:
+      return StringRef("invalid");
     case none:
       return StringRef("none");
     case branch32: 
@@ -263,6 +272,9 @@
     case subordinateLSDA:
       // do nothing
       break;
+    case invalid:
+      assert(0 && "invalid Reference Kind");
+      break;
   }
 }
 
@@ -287,13 +299,16 @@
     .Case("pointer32",          pointer32)
     .Case("lazyTarget",         lazyTarget)
     .Case("lazyImmediate",      lazyImmediate)
-    .Case("subordinateLSDA",    subordinateLSDA);
+    .Case("subordinateLSDA",    subordinateLSDA)
+    .Default(invalid);
 
   llvm_unreachable("invalid ARM Reference kind");
 }
 
 StringRef KindHandler_arm::kindToString(Reference::Kind kind) {
   switch ( (Kinds)kind ) {
+    case invalid:
+      return StringRef("invalid");
     case none:
       return StringRef("none");
     case thumbBranch22: 
@@ -375,6 +390,9 @@
     case subordinateLSDA:
       // do nothing
       break;
+    case invalid:
+      assert(0 && "invalid Reference Kind");
+      break;
   }
 }