[compiler-rt/profile] Include __llvm_profile_get_magic in module signature

[pirama]

Summary

The INSTR_PROF_RAW_MAGIC_* number in profraw files should match during
profile merging. This causes an error with 32-bit and 64-bit variants
of the same code. The module signatures for the two binaries are
identical but they use different INSTR_PROF_RAW_MAGIC_* causing a
failure when profile-merging is used. Including it when computing the
module signature yields different signatures for the 32-bit and 64-bit
profiles.

[pirama]

reword commit message.

[davidxl]

lgtm

compiler-rt/lib/profile/InstrProfilingMerge.c

uint64_t DataSize = __llvm_profile_get_data_size(__llvm_profile_begin_data(),
                                                    __llvm_profile_end_data());
   uint64_t NamesSize =
       (uint64_t)(__llvm_profile_end_names() - __llvm_profile_begin_names());
   uint64_t NumVnodes =
       (uint64_t)(__llvm_profile_end_vnodes() - __llvm_profile_begin_vnodes());
   const __llvm_profile_data *FirstD = __llvm_profile_begin_data();
 
   return (NamesSize << 40) + (CounterSize << 30) + (DataSize << 20) +
-         (NumVnodes << 10) + (DataSize > 0 ? FirstD->NameRef : 0) + Version;
+         (NumVnodes << 10) + (DataSize > 0 ? FirstD->NameRef : 0) + Version +
+         __llvm_profile_get_magic();
 }
 
 /* Returns 1 if profile is not structurally compatible.  */
 COMPILER_RT_VISIBILITY
 int __llvm_profile_check_compatibility(const char *ProfileData,
                                        uint64_t ProfileSize) {
   /* Check profile header only for now  */
   __llvm_profile_header *Header = (__llvm_profile_header *)ProfileData;