fix: TSAN data-race fixes and sanitizer CI configuration

- Fix TSAN data races in CoroTaskRunner (atomic operations, mutex guards)
- Enable TSAN CI builds with proper ucontext support
- Add TSAN suppressions for pre-existing rippled issues
- Remove -fno-pie flags for sanitizer compatibility

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/scripts/strategy-matrix/generate.py

@@ -235,11 +235,16 @@ def generate_strategy_matrix(all: bool, config: Config) -> list:
         # so that they are easier to identify in the GitHub Actions UI, as long
         # names get truncated.
         # Add Address and Thread (both coupled with UB) sanitizers for specific bookworm distros.
-        # GCC-Asan rippled-embedded tests are failing because of https://github.com/google/sanitizers/issues/856
-        if (
-            os["distro_version"] == "bookworm"
-            and f"{os['compiler_name']}-{os['compiler_version']}" == "clang-20"
-        ):
+        # Note: GCC ASAN's detect_stack_use_after_return produces false positives with
+        # Boost.Context fibers (boost::asio::spawn). Mitigated in reusable-build-test-config.yml
+        # by setting detect_stack_use_after_return=0 for GCC.
+        # See: https://github.com/google/sanitizers/issues/856
+        if os[
+            "distro_version"
+        ] == "bookworm" and f"{os['compiler_name']}-{os['compiler_version']}" in [
+            "gcc-13",
+            "clang-17",
+        ]:
             # Add ASAN + UBSAN configuration.
             configurations.append(
                 {
@@ -253,19 +258,19 @@ def generate_strategy_matrix(all: bool, config: Config) -> list:
                     "sanitizers": "address,undefinedbehavior",
                 }
             )
-            # TSAN is deactivated due to seg faults with latest compilers.
-            activate_tsan = False
+            # TSAN is activated on gcc-13 and clang-17.
+            activate_tsan = True
             if activate_tsan:
                 configurations.append(
                     {
-                        "config_name": config_name + "-tsan-ubsan",
+                        "config_name": config_name + "-tsan",
                         "cmake_args": cmake_args,
                         "cmake_target": cmake_target,
                         "build_only": build_only,
                         "build_type": build_type,
                         "os": os,
                         "architecture": architecture,
-                        "sanitizers": "thread,undefinedbehavior",
+                        "sanitizers": "thread",
                     }
                 )
         else: