Restore r125595 (reverted in r126336) with modifications:
Introduce a variable in the AsmParserExtension whether [] is valid in an
expression. If it is true, parse them like (). Enable this for ELF only.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126443 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCParser/ELFAsmParser.cpp b/lib/MC/MCParser/ELFAsmParser.cpp
index 2285a63..dcf689a 100644
--- a/lib/MC/MCParser/ELFAsmParser.cpp
+++ b/lib/MC/MCParser/ELFAsmParser.cpp
@@ -33,7 +33,9 @@
   bool SeenIdent;
 
 public:
-  ELFAsmParser() : SeenIdent(false) {}
+  ELFAsmParser() : SeenIdent(false) {
+    BracketExpressionsSupported = true;
+  }
 
   virtual void Initialize(MCAsmParser &Parser) {
     // Call the base implementation.