llvm-mc/x86: Fix bug in disambiguation of displacement operand, introduced by me
(I think).
 - We weren't properly parsing the leading parenthesized expression in something
   like 'push (4)(%eax)'.
 
 - Added ParseParenRelocatableExpression to support this. I suspect we should
   just use lookahead, though.

 - Test case to follow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74685 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-mc/AsmParser.cpp b/tools/llvm-mc/AsmParser.cpp
index 931e460..339a16d 100644
--- a/tools/llvm-mc/AsmParser.cpp
+++ b/tools/llvm-mc/AsmParser.cpp
@@ -167,6 +167,19 @@
   return false;
 }
 
+bool AsmParser::ParseParenRelocatableExpression(MCValue &Res) {
+  AsmExpr *Expr;
+  
+  SMLoc StartLoc = Lexer.getLoc();
+  if (ParseParenExpr(Expr))
+    return true;
+
+  if (!Expr->EvaluateAsRelocatable(Ctx, Res))
+    return Error(StartLoc, "expected relocatable expression");
+
+  return false;
+}
+
 static unsigned getBinOpPrecedence(asmtok::TokKind K, 
                                    AsmBinaryExpr::Opcode &Kind) {
   switch (K) {