1. [FPEnv] Evaluate constant expressions under non-default rounding modes (details)
Commit 6314f412a83d61e293e3696d4afe1797a4001ac4 by sepavloff
[FPEnv] Evaluate constant expressions under non-default rounding modes

The change implements evaluation of constant floating point expressions
under non-default rounding modes. The main objective was to support
evaluation of global variable initializers, where constant rounding mode
may be specified by `#pragma STDC FENV_ROUND`.

Differential Revision:
The file was modifiedclang/lib/Sema/SemaAttr.cpp (diff)
The file was modifiedclang/lib/AST/TextNodeDumper.cpp (diff)
The file was modifiedclang/include/clang/Basic/ (diff)
The file was modifiedclang/lib/AST/Expr.cpp (diff)
The file was addedclang/test/AST/const-fpfeatures.cpp
The file was addedclang/test/AST/const-fpfeatures-diag.c
The file was modifiedclang/include/clang/AST/Expr.h (diff)
The file was modifiedclang/lib/AST/ExprConstant.cpp (diff)
The file was addedclang/test/AST/const-fpfeatures.c