Use standard separator for TSan options in `stress.cpp` test case.

[delcypher]

Summary

Use of space as a separator for options is problematic for wrapper
scripts (i.e. implementations of %run) that have to marshall
environment variables to target different than the host.

Rather than requiring every implementation of %run to support spaces
in TSAN_OPTIONS it is simpler to fix this single test case.

rdar://83637067

[dvyukov]

It would be useful if the standard %run would detect this problem and fail.

[delcypher]

In D110967#3037926, @dvyukov wrote:

It would be useful if the standard %run would detect this problem and fail.

Thanks for the review. While I agree this would be useful I don't think this problem happens frequently enough to justify implementing what you suggested. If it continues to be a problem we can certainly revisit this.

compiler-rt/test/tsan/stress.cpp

-// RUN: %clangxx_tsan -O1 %s -o %t && %env_tsan_opts="flush_memory_ms=1 flush_symbolizer_ms=1 memory_limit_mb=1" %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_tsan -O1 %s -o %t && %env_tsan_opts=flush_memory_ms=1:flush_symbolizer_ms=1:memory_limit_mb=1 %run %t 2>&1 | FileCheck %s
 #include "test.h"
 #include <fcntl.h>
 #include <string.h>
 
 volatile long stop;
 long atomic, read_only;
 int fds[2];