Hi,

This patch merges the D front-end implementation with dmd upstream 7423993c9.

Backports a fix for extern(C++) mangling for substituted basic types
that are target-specific.  Introduces a new method that currently does
nothing, but could in future make use of flag_abi_version as
extern(C++) integration improves in latter versions of the D
front-end.

Bootstrapped and regression tested on x86_64-linux-gnu.

Committed to trunk as r269611.

-- 
Iain
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gcc/d/ChangeLog:

2019-03-12  Iain Buclaw  <ibuclaw@gdcproject.org>

        * d-lang.cc (d_init_options): Set global.params.cplusplus to C++14.
        * d-target.cc (Target::cppFundamentalType): New method.
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