Add FP_CONTRACT support for clang.

Clang will now honor the FP_CONTRACT pragma and emit LLVM
fmuladd intrinsics for expressions of the form A * B + C (when they occur in a
single statement).

llvm-svn: 164989
diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index db6b3d4..eb2a672 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -679,6 +679,11 @@
   PrettyStackTraceLoc CrashInfo(PP.getSourceManager(),
                                 Tok.getLocation(),
                                 "in compound statement ('{}')");
+
+  // Record the state of the FP_CONTRACT pragma, restore on leaving the
+  // compound statement.
+  Sema::FPContractStateRAII SaveFPContractState(Actions);
+
   InMessageExpressionRAIIObject InMessage(*this, false);
   BalancedDelimiterTracker T(*this, tok::l_brace);
   if (T.consumeOpen())