[PATCH] RISC-V: Avoid calloc() poisoning on musl

[Sam James via Gcc-patches]

This fixes errors like:
```
In file included from /usr/include/pthread.h:30,
                 from 
/usr/lib/gcc/riscv64-gentoo-linux-musl/12/include/g++-v12/riscv64-gentoo-linux-musl/bits/gthr-default.h:35,
                 from 
/usr/lib/gcc/riscv64-gentoo-linux-musl/12/include/g++-v12/riscv64-gentoo-linux-musl/bits/gthr.h:148,
                 from 
/usr/lib/gcc/riscv64-gentoo-linux-musl/12/include/g++-v12/ext/atomicity.h:35,
                 from 
/usr/lib/gcc/riscv64-gentoo-linux-musl/12/include/g++-v12/bits/ios_base.h:39,
                 from 
/usr/lib/gcc/riscv64-gentoo-linux-musl/12/include/g++-v12/ios:42,
                 from 
/usr/lib/gcc/riscv64-gentoo-linux-musl/12/include/g++-v12/istream:38,
                 from 
/usr/lib/gcc/riscv64-gentoo-linux-musl/12/include/g++-v12/sstream:38,
                 from 
/var/tmp/portage/sys-devel/gcc-13.0.1_pre20230305/work/gcc-13-20230305/gcc/config/riscv/genrvv-type-indexer.cc:22:
/usr/include/sched.h:84:7: error: attempt to use poisoned "calloc"
   84 | void *calloc(size_t, size_t);
      |       ^
/usr/include/sched.h:124:36: error: attempt to use poisoned "calloc"
  124 | #define CPU_ALLOC(n) ((cpu_set_t *)calloc(1,CPU_ALLOC_SIZE(n)))
      |                                    ^
make[3]: *** [Makefile:2855: build/genrvv-type-indexer.o] Error 1
```

See also 3b21c21f3f5726823e19728fdd1571a14aae0fb3 and 
49d508065bdd36fb1a9b6aad9666b1edb5e06474,
which was fixed in PR106102.

gcc/ChangeLog:
        * config/riscv/genrvv-type-indexer.cc: Add missing <pthread.h> include.

Signed-off-by: Sam James <s...@gentoo.org>
---
 gcc/ChangeLog                           | 5 +++++
 gcc/config/riscv/genrvv-type-indexer.cc | 1 +
 2 files changed, 6 insertions(+)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c9e557ce833..7783b2f4cd2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2023-03-11  Sam James  <s...@gentoo.org>
+
+       * config/riscv/genrvv-type-indexer.cc: Add missing <pthread.h> include
+       for musl compatibility.
+
 2023-03-10  Jakub Jelinek  <ja...@redhat.com>
 
        PR target/107703
diff --git a/gcc/config/riscv/genrvv-type-indexer.cc 
b/gcc/config/riscv/genrvv-type-indexer.cc
index 0ef1d766002..b286ec84132 100644
--- a/gcc/config/riscv/genrvv-type-indexer.cc
+++ b/gcc/config/riscv/genrvv-type-indexer.cc
@@ -14,6 +14,7 @@ along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
 
 #include "bconfig.h"
+#define INCLUDE_PTHREAD_H
 #include "system.h"
 #include "errors.h"
 
-- 
2.39.2