Currently EH lowering code expects typeinfo to be global only.
This assumption is not satisfied due to global mergeing.
Workaround the issue by temporary disablinge mergeing of const globals.
Also, ignore LLVM "special" globals. This fixes PR7716

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109423 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMGlobalMerge.cpp b/lib/Target/ARM/ARMGlobalMerge.cpp
index cb7947b2..af7298a 100644
--- a/lib/Target/ARM/ARMGlobalMerge.cpp
+++ b/lib/Target/ARM/ARMGlobalMerge.cpp
@@ -178,6 +178,11 @@
     if (I->getAlignment() != 0)
       continue;
 
+    // Ignore all 'special' globals.
+    if (I->getName().startswith("llvm.") ||
+        I->getName().startswith(".llvm."))
+      continue;
+
     if (TD->getTypeAllocSize(I->getType()) < MaxOffset) {
       if (I->isConstant())
         ConstGlobals.push_back(I);
@@ -188,8 +193,12 @@
 
   if (Globals.size() > 1)
     Changed |= doMerge(Globals, M, false);
-  if (ConstGlobals.size() > 1)
-    Changed |= doMerge(ConstGlobals, M, true);
+  // FIXME: This currently breaks the EH processing due to way how the 
+  // typeinfo detection works. We might want to detect the TIs and ignore 
+  // them in the future.
+  
+  // if (ConstGlobals.size() > 1)
+  //  Changed |= doMerge(ConstGlobals, M, true);
 
   return Changed;
 }