Fix mips build with GCC 9 [committed]

[Joseph Myers]

This patch fixes the build for MIPS (o32) with GCC 9 by stopping MIPS
__longjmp from using strong_alias, instead defining the alias
manually, so that the intended effect of not copying the nomips16
attribute is achieved, as explained in the included comment.

Tested with build-many-glibcs.py compilers build for mips64-linux-gnu
(which includes glibc builds for all three ABIs). Committed.

2018-11-13 Joseph Myers <***@codesourcery.com>

* sysdeps/mips/__longjmp.c (__longjmp): Define alias manually with
alias attribute, not with strong_alias.

diff --git a/sysdeps/mips/__longjmp.c b/sysdeps/mips/__longjmp.c
index 56bb73f1bc..7c95bc4030 100644
--- a/sysdeps/mips/__longjmp.c
+++ b/sysdeps/mips/__longjmp.c
@@ -81,4 +81,9 @@ ____longjmp (__jmp_buf env_arg, int val_arg)
for (;;);
}

-strong_alias (____longjmp, __longjmp);
+/* Not using strong_alias because the nomips16 attribute cannot be
+ copied from ____longjmp to __longjmp, because of the
+ architecture-independent declaration of __longjmp without the
+ attribute and compiler errors for such attributes not being the
+ same on all declarations. */
+extern __typeof (____longjmp) __longjmp __attribute__ ((alias ("____longjmp")));