Update lang/gcc and hence the default version of GCC in the Ports

Collection (requested by USE_GCC=yes and various USES=compiler
invocations) from GCC 4.9.4 to GCC 5.4.

files/patch-arm-support and files/patch-gcc_system.h have become
obsolete.  New patches files/patch-arm-unwind-cxx-support and
files/patch-libc++ help support arm targets and new libc++ in base.

ONLY_FOR_ARCHS now also includes arm.

A new option GRAPHITE_DESC, off by default for now, adds support for
Graphite loop optimizations.

Finally, conflicts with other lang/gcc* ports are adjusted suitably.

In terms of changes for users, this upgrade brings the following:

The default mode for C is now -std=gnu11 instead of -std=gnu89.
New warning options -Wc90-c99-compat and -Wc99-c11-compat may
prove useful on that front.

The C++ front end now has full C++14 language support including
C++14 variable templates, C++14 aggregates with non-static data
member initializers, C++14 extended constexpr, and more.
The Standard C++ Library (libstdc++) has full C++11 support and
experimental full C++14 support.  It uses a new ABI by default.

There have been significant improvements to inter-procedural optimizations
and link-time optimization such as One Definition Rule based merging of C++
types as well as register allocation.

OpenMP 4.0 specification offloading features are now supported by the C,
C++, and Fortran compilers.  Cilk Plus, an extension to the C and C++
languages to support data and task parallelism, has been added as well.

New warning options -Wswitch-bool, -Wlogical-not-parentheses,
-Wbool-compare and -Wsizeof-array-argument may prove useful as
may new preprocessor directives __has_include, __has_include_next,
and __has_attribute.

GCC can now be built as a shared library for embedding in other processes
(such as interpreters), suitable for Just-In-Time compilation to machine
code.  This provides a C API and a C++ wrapper API.

Many code generation improvements for AArch64, ARM, support for
AVX-512{BW,DQ,VL,IFMA,VBMI} and Intel MPX on x86-64, and generally
improvements on many targets.

The Local Register Allocator (LRA) now contains a rematerialization
subpass and is able to reuse the PIC hard register on x86/x86-64 to
improve performance of position independent code.

https://gcc.gnu.org/gcc-5/changes.html has a more extensive set of
changes and https://gcc.gnu.org/gcc-5/porting_to.html has a solid
overview of issue you may encountering porting to this new version.

PR:             216707, 218125
Tested by:      antoine (-exp runs)
Supported by:   jbeich, tcberner, and others

1 files changed, 106 insertions, 0 deletions

diff --git a/lang/gcc/files/patch-arm-unwind-cxx-support b/lang/gcc/files/patch-arm-unwind-cxx-support
new file mode 100644
index 000000000000..ec6959b9655c
--- /dev/null
+++ b/lang/gcc/files/patch-arm-unwind-cxx-support
@@ -0,0 +1,106 @@
+--- UTC
+Index: gcc/ginclude/unwind-arm-common.h
+===================================================================
+--- gcc/ginclude/unwind-arm-common.h	(revision 219113)
++++ gcc/ginclude/unwind-arm-common.h	(working copy)
+@@ -82,7 +82,11 @@
+ 
+   struct _Unwind_Control_Block
+     {
++#ifdef __FreeBSD__
++      unsigned exception_class __attribute__((__mode__(__DI__)));
++#else
+       char exception_class[8];
++#endif
+       void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block *);
+       /* Unwinder cache, private fields for the unwinder's use */
+       struct
+@@ -181,7 +185,11 @@
+ 
+   /* Support functions for the PR.  */
+ #define _Unwind_Exception _Unwind_Control_Block
++#ifdef __FreeBSD__
++  typedef unsigned _Unwind_Exception_Class __attribute__((__mode__(__DI__)));
++#else
+   typedef char _Unwind_Exception_Class[8];
++#endif
+ 
+   void * _Unwind_GetLanguageSpecificData (_Unwind_Context *);
+   _Unwind_Ptr _Unwind_GetRegionStart (_Unwind_Context *);
+Index: libstdc++-v3/libsupc++/unwind-cxx.h
+===================================================================
+--- libstdc++-v3/libsupc++/unwind-cxx.h	(revision 219147)
++++ libstdc++-v3/libsupc++/unwind-cxx.h	(working copy)
+@@ -235,7 +235,7 @@
+   return reinterpret_cast<__cxa_dependent_exception *>(exc + 1) - 1;
+ }
+ 
+-#ifdef __ARM_EABI_UNWINDER__
++#if defined(__ARM_EABI_UNWINDER__) && !defined(__FreeBSD__)
+ static inline bool
+ __is_gxx_exception_class(_Unwind_Exception_Class c)
+ {
+@@ -309,13 +309,7 @@
+   c[6] = 'R';
+   c[7] = '\0';
+ }
+-
+-static inline void*
+-__gxx_caught_object(_Unwind_Exception* eo)
+-{
+-  return (void*)eo->barrier_cache.bitpattern[0];
+-}
+-#else // !__ARM_EABI_UNWINDER__
++#else // !__ARM_EABI_UNWINDER__ || __FreeBSD__
+ // This is the primary exception class we report -- "GNUCC++\0".
+ const _Unwind_Exception_Class __gxx_primary_exception_class
+ = ((((((((_Unwind_Exception_Class) 'G' 
+@@ -339,6 +333,16 @@
+     << 8 | (_Unwind_Exception_Class) '+')
+    << 8 | (_Unwind_Exception_Class) '\x01');
+ 
++const _Unwind_Exception_Class __gxx_forced_unwind_class
++= ((((((((_Unwind_Exception_Class) 'G'
++        << 8 | (_Unwind_Exception_Class) 'N')
++       << 8 | (_Unwind_Exception_Class) 'U')
++      << 8 | (_Unwind_Exception_Class) 'C')
++     << 8 | (_Unwind_Exception_Class) 'F')
++    << 8 | (_Unwind_Exception_Class) 'O')
++   << 8 | (_Unwind_Exception_Class) 'R')
++  << 8 | (_Unwind_Exception_Class) '\0');
++
+ static inline bool
+ __is_gxx_exception_class(_Unwind_Exception_Class c)
+ {
+@@ -346,6 +350,12 @@
+       || c == __gxx_dependent_exception_class;
+ }
+ 
++static inline bool
++__is_gxx_forced_unwind_class(_Unwind_Exception_Class c)
++{
++  return c ==  __gxx_forced_unwind_class;
++}
++
+ // Only checks for primary or dependent, but not that it is a C++ exception at
+ // all.
+ static inline bool
+@@ -357,7 +367,18 @@
+ #define __GXX_INIT_PRIMARY_EXCEPTION_CLASS(c) c = __gxx_primary_exception_class
+ #define __GXX_INIT_DEPENDENT_EXCEPTION_CLASS(c) \
+   c = __gxx_dependent_exception_class
++#define __GXX_INIT_FORCED_UNWIND_CLASS(c) c = __gxx_forced_unwind_class 
++#endif // __ARM_EABI_UNWINDER__ && !__FreeBSD__
+ 
++#ifdef __ARM_EABI_UNWINDER__
++static inline void*
++__gxx_caught_object(_Unwind_Exception* eo)
++{
++    return (void*)eo->barrier_cache.bitpattern[0];
++}
++
++#else // !__ARM_EABI_UNWINDER__
++
+ // GNU C++ personality routine, Version 0.
+ extern "C" _Unwind_Reason_Code __gxx_personality_v0
+      (int, _Unwind_Action, _Unwind_Exception_Class,