[PATCH] xen: Update minimum toolchain requirements

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

GCC 4.1.2 is from 2007, and Binutils 2.16 is a similar vintage.  Clang 3.5 is
from 2014.  Supporting toolchains this old is a massive development and
testing burden.

Set a minimum baseline of GCC 5.1 across the board, along with Binutils 2.25
which is the same age.  These were chosen *3 years ago* as Linux's minimum
requirements because even back then, they were ubiquitous in distros.  Choose
Clang/LLVM 11 as a baseline for similar reasons; the Linux commit making this
change two years ago cites a laudry list of code generation bugs.

This will allow us to retire a lot of compatiblity logic, and start using new
features previously unavailable because of no viable compatibility option.

Merge the ARM 32bit and 64bit sections now they're the same.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Anthony PERARD <anthony.perard@xxxxxxxxxx>
CC: Michal Orzel <michal.orzel@xxxxxxx>
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
CC: Bertrand Marquis <bertrand.marquis@xxxxxxx>
CC: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
CC: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>

PPC doesn't have a minimum set stated yet, but CI tests GCC 10 from Debian 11.

This will require dropping some containers from CI.  CentOS 7 notably.

In terms of specific new features, I'm interested in:

 * __has_include() to remove the asm-generic makefile tangle
 * asm goto (), to remove .fixup and code generation for error handling.

and these too, but will require MISRA adjustments:

 * _Generic() to make properly const-preserving wrappers
 * Updating our -std to gnu11, which drops further compatibility logic

When the arguments die down, I'll add a hunk to CHANGELOG.md as this is very
significant.
---
 README | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/README b/README
index 9d9c6fc324c6..be90be3910d4 100644
--- a/README
+++ b/README
@@ -38,16 +38,13 @@ provided by your OS distributor:
     * GNU Make v3.80 or later
     * C compiler and linker:
       - For x86:
-        - GCC 4.1.2_20070115 or later
-        - GNU Binutils 2.16.91.0.5 or later
+        - GCC 5.1 or later
+        - GNU Binutils 2.25 or later
         or
-        - Clang/LLVM 3.5 or later
-      - For ARM 32-bit:
-        - GCC 4.9 or later
-        - GNU Binutils 2.24 or later
-      - For ARM 64-bit:
+        - Clang/LLVM 11 or later
+      - For ARM:
         - GCC 5.1 or later
-        - GNU Binutils 2.24 or later
+        - GNU Binutils 2.25 or later
       - For RISC-V 64-bit:
         - GCC 12.2 or later
         - GNU Binutils 2.39 or later

base-commit: ac29d63a0fa6a3ed98ecf86f95995811c301308f
-- 
2.39.5