gdb: Document C++17 build requirement.
We require C++17 to build for a while now:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=f74dc26792a0679e29db45e56367331ff48666d1
Reviewed-By: Lancelot Six <lancelot.six@amd.com>
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index e4b89cf..7980548 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -40555,9 +40555,9 @@
@heading Tools/Packages Necessary for Building @value{GDBN}
@table @asis
-@item C@t{++}11 compiler
-@value{GDBN} is written in C@t{++}11. It should be buildable with any
-recent C@t{++}11 compiler, e.g.@: GCC.
+@item C@t{++}17 compiler
+@value{GDBN} is written in C@t{++}17. It should be buildable with any
+recent C@t{++}17 compiler, e.g.@: GCC.
@item GNU make
@value{GDBN}'s build system relies on features only found in the GNU
