Rebased PNaCl localmods in LLVM to 223109

lib/Target/X86/AsmParser/X86AsmParser.cpp

Index: lib/Target/X86/AsmParser/X86AsmParser.cpp
diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 8ef2a5558da321e0e60f34676af6c1045089c3d9..a6c91329c2287b4670cdb0b5fc0f99770320b1b1 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -2753,7 +2753,18 @@ bool X86AsmParser::ParseDirective(AsmToken DirectiveID) {
                                            "a '%' prefix in .intel_syntax");
     }
     return false;
+  // @LOCALMOD-START
+  } else if (IDVal.startswith(".dwarf_addr_size")) {
+    // For compatibility with NaCl gas, which needs to override the size of
+    // DWARF address values on x86-64 (normally it assumes that the address size
+    // matches the ELF class, which is not currently true for x86-64 NaCl).
+    // Require the size to be 4, since that matches the module address size.
+    if (Parser.getTok().getString() != "4")
+      return Error(DirectiveID.getLoc(), ".dwarf_addr_size must be 4");
+    Parser.Lex();
+    return false;
   }
+  // @LOCALMOD-END
   return true;
 }