[lldb] Improve swift-healthcheck help message (NFC) (#4990)

rdar://93660209


(cherry-picked from commit de3ee07)

Author: kastiglione

lldb/source/Commands/CommandObjectHealthcheck.cpp

@@ -22,9 +22,13 @@ using namespace lldb_private;
 
 CommandObjectHealthcheck::CommandObjectHealthcheck(
     CommandInterpreter &interpreter)
-    : CommandObjectParsed(interpreter, "swift-healthcheck",
-                          "Show the LLDB debugger health check diagnostics.",
-                          "swift-healthcheck") {}
+    : CommandObjectParsed(
+          interpreter, "swift-healthcheck",
+          "Provides logging related to the Swift expression evaluator, "
+          "including Swift compiler diagnostics. This makes it easier to "
+          "identify project misconfigurations that result in module import "
+          "failures in the debugger. The command is meant to be run after a "
+          "expression evaluator failure has occurred.") {}
 
 bool CommandObjectHealthcheck::DoExecute(Args &args,
                                          CommandReturnObject &result) {

lldb/test/API/lang/swift/swift-healthcheck/TestSwiftHealthCheck.py

@@ -12,7 +12,7 @@ class TestSwiftHealthCheck(TestBase):
 
     @swiftTest
     @skipIfDarwinEmbedded
-    def test(self):
+    def test_run_healthcheck(self):
         """Test that an underspecified triple is upgraded with a version number.
         """
         self.build()
@@ -37,3 +37,9 @@ def test(self):
                 break
         self.assertGreater(good, 1)
         self.assertEquals(bad, 0)
+
+    @swiftTest
+    @skipIfDarwinEmbedded
+    def test_help_healthcheck(self):
+        self.expect("help swift-healthcheck",
+                    substrs=["logging related to the Swift expression evaluator"])