[gdb/testsuite] Fix gdb.python/py-inferior.exp with -fsanitize=thread

With a gdb build with -fsanitize=thread, and test-case
gdb.python/py-inferior.exp I run into:
...
(gdb) python gdb.selected_inferior().read_memory (0, 0xffffffffffffffff)^M
ERROR: ThreadSanitizer: requested allocation size 0xffffffffffffffff exceeds \
  maximum supported size of 0x10000000000^M
...

There's already a workaround for this using ASAN_OPTIONS, and apparently the
same is needed for TSAN_OPTIONS.

Add the allocator_may_return_null=1 workaround also in TSAN_OPTIONS.

Likewise in gdb.dap/memory.exp.

Tested on x86_64-linux.

1 files changed, 2 insertions, 1 deletions

diff --git a/gdb/testsuite/gdb.dap/memory.exp b/gdb/testsuite/gdb.dap/memory.exp
index 7082706..c4e4fb3 100644
--- a/gdb/testsuite/gdb.dap/memory.exp
+++ b/gdb/testsuite/gdb.dap/memory.exp
@@ -25,11 +25,12 @@ if {[build_executable ${testfile}.exp $testfile] == -1} {
     return
 }
 
-save_vars { env(ASAN_OPTIONS) } {
+save_vars { env(ASAN_OPTIONS) env(TSAN_OPTIONS) } {
     # The request readMemory with count 18446744073709551615 triggers address
     # sanitizer.  Suppress the error, leaving us with just this warning:
     #   WARNING: AddressSanitizer failed to allocate 0xffffffffffffffff bytes
     set_sanitizer ASAN_OPTIONS allocator_may_return_null 1
+    set_sanitizer TSAN_OPTIONS allocator_may_return_null 1
 
     if {[dap_initialize] == ""} {
 	return