merge GCC 9.3.0.

merge GCC 8.3.0 pass 1. will not compile yet. thare are still
about 25 files with merge issues.

branches: 1.3.4;
merge GCC 6.4.0. sanitizer stuff is probably busted, but most
other changes merged easily.

docs need to be regenerated with modern versions still.

use AC_USE_SYSTEM_EXTENSIONS in libiberty autoconf, which arranges for
_GNU_SOURCE to be defined for systems that need it (like glibc ones.)

be sure to find the right config.h for host programs.

these fixes combined make builds on debian 7 complete for me.

branches: 1.1.1;
Initial revision

merge GCC 8.3.0 pass 1. will not compile yet. thare are still
about 25 files with merge issues.

merge GCC 6.4.0. sanitizer stuff is probably busted, but most
other changes merged easily.

docs need to be regenerated with modern versions still.

use AC_USE_SYSTEM_EXTENSIONS in libiberty autoconf, which arranges for
_GNU_SOURCE to be defined for systems that need it (like glibc ones.)

be sure to find the right config.h for host programs.

these fixes combined make builds on debian 7 complete for me.

branches: 1.1.1;
Initial revision

merge GCC 6.4.0. sanitizer stuff is probably busted, but most
other changes merged easily.

docs need to be regenerated with modern versions still.

use AC_USE_SYSTEM_EXTENSIONS in libiberty autoconf, which arranges for
_GNU_SOURCE to be defined for systems that need it (like glibc ones.)

be sure to find the right config.h for host programs.

these fixes combined make builds on debian 7 complete for me.

branches: 1.1.1;
Initial revision

use AC_USE_SYSTEM_EXTENSIONS in libiberty autoconf, which arranges for
_GNU_SOURCE to be defined for systems that need it (like glibc ones.)

be sure to find the right config.h for host programs.

these fixes combined make builds on debian 7 complete for me.

branches: 1.1.1;
Initial revision

branches: 1.1.1;
Initial revision

import GCC 4.8 branch at r206687.

highlights from: http://gcc.gnu.org/gcc-4.6/changes.html

GCC now has stricter checks for invalid command-line options
New -Wunused-but-set-variable and -Wunused-but-set-parameter
warnings
Many platforms have been obsoleted
Link-time optimization improvements
A new switch -fstack-usage has been added
A new function attribute leaf was introduced
A new warning, enabled by -Wdouble-promotion
Support for selectively enabling and disabling warnings via
#pragma GCC diagnostic has been added
There is now experimental support for some features from the
upcoming C1X revision of the ISO C standard
Improved experimental support for the upcoming C++0x ISO C++
standard
G++ now issues clearer diagnostics in several cases
Updates for ARM, x86, MIPS, PPC/PPC64, SPARC
Darwin, FreeBSD, Solaris 2, MinGW and Cygwin now all support
__float128 on 32-bit and 64-bit x86 targets. [*1]

highlights from: http://gcc.gnu.org/gcc-4.7/changes.html

The -fconserve-space flag has been deprecated
Support for a new parameter --param case-values-threshold=n
was added
Interprocedural and Link-time optimization improvements
A new built-in, __builtin_assume_aligned, has been added
A new warning option -Wunused-local-typedefs was added
A new experimental command-line option -ftrack-macro-expansion
was added
Support for atomic operations specifying the C++11/C11 memory
model has been added
There is support for some more features from the C11 revision
of the ISO C standard
Improved experimental support for the new ISO C++ standard,
C++11
Updates for ARM, x86, MIPS, PPC/PPC64, SH, SPARC, TILE*
A new option (-grecord-gcc-switches) was added

highlights from: http://gcc.gnu.org/gcc-4.8/changes.html

GCC now uses C++ as its implementation language. This means
that to build GCC from sources, you will need a C++
compiler that understands C++ 2003
DWARF4 is now the default when generating DWARF debug
information
A new general optimization level, -Og, has been introduced
A new option -ftree-partial-pre was added
The option -fconserve-space has been removed
The command-line options -fipa-struct-reorg and
-fipa-matrix-reorg have been removed
Interprocedural and Link-time optimization improvements
AddressSanitizer, a fast memory error detector, has been
added [*2]
A new -Wsizeof-pointer-memaccess warning has been added
G++ now supports a -std=c++1y option for experimentation
with features proposed for the next revision of the
standard, expected around 2014
Improved experimental support for the new ISO C++ standard,
C++11
A new port has been added to support AArch64
Updates for ARM, x86, MIPS, PPC/PPC64, SH, SPARC, TILE*


[*1] we should support this too!
[*2] we should look into this.
https://code.google.com/p/address-sanitizer/

branches: 1.1.1.1.2; 1.1.1.1.8;
initial import of GCC 4.5.3 sources. changes since 4.1 are way too numerous
to review, please see http://gcc.gnu.org/gcc-4.5/changes.html (and the 4.2,
4.3 and 4.4 versions, too.)

this includes the core, c++, objc and the non java/ada/fortran parts of the
testsuite.

Rebase to HEAD as of a few days ago.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs. ("Protocol error: too many arguments")