Enhance regrtest get_signal_name(): support shell exit code (python#117647)

Author: vstinner

Lib/test/libregrtest/utils.py

@@ -698,6 +698,14 @@ def get_signal_name(exitcode):
         except ValueError:
             pass
 
+    # Shell exit code (ex: WASI build)
+    if 128 < exitcode < 256:
+        signum = exitcode - 128
+        try:
+            return signal.Signals(signum).name
+        except ValueError:
+            pass
+
     try:
         return WINDOWS_STATUS[exitcode]
     except KeyError:

Lib/test/test_regrtest.py

@@ -2291,6 +2291,7 @@ def test_get_signal_name(self):
         for exitcode, expected in (
             (-int(signal.SIGINT), 'SIGINT'),
             (-int(signal.SIGSEGV), 'SIGSEGV'),
+            (128 + int(signal.SIGABRT), 'SIGABRT'),
             (3221225477, "STATUS_ACCESS_VIOLATION"),
             (0xC00000FD, "STATUS_STACK_OVERFLOW"),
         ):