glibc: fix inconsistency of mips ABI mapping

Before this commit, glibc headers did the following mapping:

 * (zig) mipsel-linux-gnu      => (glibc) mipsel-linux-gnu
 * (zig) mipsel-linux-gnu-soft => (glibc) (none)
 * (zig) mips-linux-gnu        => (glibc) mips-linux-gnu
 * (zig) mips-linux-gnu-soft   => (glibc) (none)

While the glibc ABI stubs used the (zig) gnueabi and gnueabihf ABIs,
and the stage2 available_libcs array listed:

 * (zig) mipsel-linux-gnu
 * (zig) mips-linux-gnu

The problem is the mismatch between the ABI component of the headers and
the stubs.

This commit makes the following clarifications:

 * (zig) mips-linux-gnueabi     means soft-float
 * (zig) mipsel-linux-gnueabi   means soft-float
 * (zig) mips-linux-gnueabihf   means hard-float
 * (zig) mipsel-linux-gnueabihf means hard-float

Consequently, the glibc headers now do this mapping:

 * (zig) mips-linux-gnueabihf   => (glibc) mips-linux-gnu
 * (zig) mipsel-linux-gnueabihf => (glibc) mipsel-linux-gnu
 * (zig) mips-linux-gnueabi     => (glibc) mips-linux-gnu-soft
 * (zig) mipsel-linux-gnueabi   => (glibc) mipsel-linux-gnu-soft

The glibc ABI stubs are unchanged, and the stage2 available_libcs
array's 2 entries are modified and it gains 2 more:

 * (zig) mipsel-linux-gnueabi
 * (zig) mipsel-linux-gnueabihf
 * (zig) mips-linux-gnueabi
 * (zig) mips-linux-gnueabihf

Now everything is consistent. Zig no longer recognizes a `mips-linux-gnu`
triple; one must use `mips-linux-gnueabi` (soft float) or
`mips-linux-gnueabihf` (hard float).

1 files changed, 52 insertions, 0 deletions

diff --git a/lib/libc/include/arm-linux-gnueabi/bits/floatn.h b/lib/libc/include/arm-linux-gnueabi/bits/floatn.h
new file mode 100644
index 0000000000..18018fa9f8
--- /dev/null
+++ b/lib/libc/include/arm-linux-gnueabi/bits/floatn.h
@@ -0,0 +1,52 @@
+/* Macros to control TS 18661-3 glibc features.
+   Copyright (C) 2017-2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* Defined to 1 if the current compiler invocation provides a
+   floating-point type with the IEEE 754 binary128 format, and this glibc
+   includes corresponding *f128 interfaces for it.  */
+#define __HAVE_FLOAT128 0
+
+/* Defined to 1 if __HAVE_FLOAT128 is 1 and the type is ABI-distinct
+   from the default float, double and long double types in this glibc.  */
+#define __HAVE_DISTINCT_FLOAT128 0
+
+/* Defined to 1 if the current compiler invocation provides a
+   floating-point type with the right format for _Float64x, and this
+   glibc includes corresponding *f64x interfaces for it.  */
+#define __HAVE_FLOAT64X 0
+
+/* Defined to 1 if __HAVE_FLOAT64X is 1 and _Float64x has the format
+   of long double.  Otherwise, if __HAVE_FLOAT64X is 1, _Float64x has
+   the format of _Float128, which must be different from that of long
+   double.  */
+#define __HAVE_FLOAT64X_LONG_DOUBLE 0
+
+#ifndef __ASSEMBLER__
+
+/* Defined to concatenate the literal suffix to be used with _Float128
+   types, if __HAVE_FLOAT128 is 1.
+   E.g.: #define __f128(x) x##f128.  */
+# undef __f128
+
+/* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.
+   E.g.: #define __CFLOAT128 _Complex _Float128.  */
+# undef __CFLOAT128
+
+#endif /* !__ASSEMBLER__.  */
+
+#include <bits/floatn-common.h>
\ No newline at end of file