[PATCH v4 1/2] 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: Avoid calloc() poisoning on musl 
by
        including <sstream> earlier.
        * system.h: Add INCLUDE_SSTREAM.

Signed-off-by: Sam James <s...@gentoo.org>
---
 gcc/config/riscv/genrvv-type-indexer.cc | 2 +-
 gcc/system.h                            | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/config/riscv/genrvv-type-indexer.cc 
b/gcc/config/riscv/genrvv-type-indexer.cc
index 0ef1d766002..e677b55290c 100644
--- a/gcc/config/riscv/genrvv-type-indexer.cc
+++ b/gcc/config/riscv/genrvv-type-indexer.cc
@@ -14,12 +14,12 @@ along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
 
 #include "bconfig.h"
+#define INCLUDE_SSTREAM
 #include "system.h"
 #include "errors.h"
 
 #include "coretypes.h"
 
-#include <sstream>
 #include <assert.h>
 #include <math.h>
 
diff --git a/gcc/system.h b/gcc/system.h
index 64cd5a49258..cf45db3f97e 100644
--- a/gcc/system.h
+++ b/gcc/system.h
@@ -751,6 +751,10 @@ extern int vsnprintf (char *, size_t, const char *, 
va_list);
 # include <mutex>
 #endif
 
+#ifdef INCLUDE_SSTREAM
+# include <sstream>
+#endif
+
 #ifdef INCLUDE_MALLOC_H
 #if defined(HAVE_MALLINFO) || defined(HAVE_MALLINFO2)
 #include <malloc.h>
-- 
2.40.0