Fast-math flags for LLVM IR parsing and printing

Added in the ability to read LLVM IR text that contains fast-math flags as a sequence of capital letters separated by spaces in any order. Added in the printing of the fast-math flags in a canonical order, and don't print the other flags when 'fast' is specified, as 'fast' implies all the others.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168645 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AsmParser/LLLexer.cpp

@@ -402,7 +402,7 @@ lltok::Kind LLLexer::LexExclaim() {
   }
   return lltok::exclaim;
 }
-  
+
 /// LexIdentifier: Handle several related productions:
 ///    Label           [-a-zA-Z$._0-9]+:
 ///    IntegerType     i[0-9]+
@@ -498,6 +498,11 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(seq_cst);
   KEYWORD(singlethread);
 
+  KEYWORD(nnan)
+  KEYWORD(ninf)
+  KEYWORD(nsz)
+  KEYWORD(arcp)
+  KEYWORD(fast)
   KEYWORD(nuw);
   KEYWORD(nsw);
   KEYWORD(exact);