LangOptions cannot depend on ASTContext, make it not use ASTContext directly

Fixes a layering violation introduced in 2ba4e3a4598b165245c581c506a813cd4a7dce33.
diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index 75be18e..97e9694 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -2929,7 +2929,7 @@
   Result.RHS = Visit(E->getRHS());
   Result.Ty  = E->getType();
   Result.Opcode = E->getOpcode();
-  Result.FPFeatures = E->getFPFeatures(CGF.getContext());
+  Result.FPFeatures = E->getFPFeatures(CGF.getLangOpts());
   Result.E = E;
   return Result;
 }
@@ -2949,7 +2949,7 @@
   OpInfo.RHS = Visit(E->getRHS());
   OpInfo.Ty = E->getComputationResultType();
   OpInfo.Opcode = E->getOpcode();
-  OpInfo.FPFeatures = E->getFPFeatures(CGF.getContext());
+  OpInfo.FPFeatures = E->getFPFeatures(CGF.getLangOpts());
   OpInfo.E = E;
   // Load/convert the LHS.
   LValue LHSLV = EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);