[sanitizer-common] Delete ancient glibc TLS workaround

[MaskRay]

Summary

rL156542 introduced this to work around very old glibc. This should be no longer needed.

[MaskRay]

My understanding was incorrect:( On glibc/musl and potentially other libc implementations, the static TLS range may be part of the allocated thread stack. *stk_size -= *tls_size; looks a bit weird, though. Hope D98926 sticks and fixes the problem

compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp

#if SANITIZER_GO
   *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
 #else
   GetTls(tls_addr, tls_size);
 
   uptr stack_top, stack_bottom;
   GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
   *stk_addr = stack_bottom;
   *stk_size = stack_top - stack_bottom;
-
-  if (!main) {
-    // If stack and tls intersect, make them non-intersecting.
-    if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
-      CHECK_GT(*tls_addr + *tls_size, *stk_addr);
-      CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size);
-      *stk_size -= *tls_size;
-      *tls_addr = *stk_addr + *stk_size;
-    }
-  }
 #endif
 }
 
 #if !SANITIZER_FREEBSD
 typedef ElfW(Phdr) Elf_Phdr;
 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001  // v9.2
 #define Elf_Phdr XElf32_Phdr
 #define dl_phdr_info xdl_phdr_info