[Scudo] enabling anonymous named pages on Linux 5.17 and onwards.

[RKSimon]

@devnexen This looks like its causing problems on the ppc buildbots:
https://lab.llvm.org/buildbot/#/builders/100/builds/14355
https://lab.llvm.org/buildbot/#/builders/121/builds/18122
https://lab.llvm.org/buildbot/#/builders/105/builds/23720

[abrachet]

Seeing the same issues on some downstream bots. See for example https://ci.chromium.org/ui/p/fuchsia/builders/toolchain.ci/clang-linux-arm64/b8817718220408284977/overview

compiler-rt/lib/scudo/standalone/linux.cpp

 #include <string.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>
 
-#if SCUDO_ANDROID
 #include <sys/prctl.h>
-// Definitions of prctl arguments to set a vma name in Android kernels.
-#define ANDROID_PR_SET_VMA 0x53564d41
-#define ANDROID_PR_SET_VMA_ANON_NAME 0
+// Definitions of prctl arguments to set a vma name in kernels (Linux from 5.17).
+#ifndef PR_SET_VMA
+#define PR_SET_VMA 0x53564d41
+#define PR_SET_VMA_ANON_NAME 0
 #endif
 
 namespace scudo {
 
 uptr getPageSize() { return static_cast<uptr>(sysconf(_SC_PAGESIZE)); }
 
 void NORETURN die() { abort(); }
 
#endif
   if (Addr)
     MmapFlags |= MAP_FIXED;
   void *P = mmap(Addr, Size, MmapProt, MmapFlags, -1, 0);
   if (P == MAP_FAILED) {
     if (!(Flags & MAP_ALLOWNOMEM) || errno != ENOMEM)
       dieOnMapUnmapError(errno == ENOMEM ? Size : 0);
     return nullptr;
   }
-#if SCUDO_ANDROID
   if (Name)
-    prctl(ANDROID_PR_SET_VMA, ANDROID_PR_SET_VMA_ANON_NAME, P, Size, Name);
-#endif
+    prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, P, Size, Name);
   return P;
 }
 
 void unmap(void *Addr, uptr Size, UNUSED uptr Flags,
            UNUSED MapPlatformData *Data) {
   if (munmap(Addr, Size) != 0)
     dieOnMapUnmapError();
 }