build: add version-specific library path for AIX

Add the version-specific directory containing the C/C++ runtime
libraries to `-blibpath` on AIX. This will help link `node` against
the correct libraries at run-time when compiled with a different
version of the GNU C/C++ compiler without having to manually set
a `LIBPATH` environment variable.

PR-URL: nodejs#53585
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Beth Griggs <bethanyngriggs@gmail.com>

doc: fix doc for correct usage with plan & TextContext

Fixed section in the doc that describes a test that uses the ⁠plan
feature in the test-runner.
However, the test in this example fails.
The fix use  (Textcontext) and reduce the plan number
to 1 since we have 1 assertion.

Author: richardlau

common.gypi

@@ -579,6 +579,9 @@
               '-Wl,-brtl',
             ],
           }, {                                             # else it's `AIX`
+            'variables': {
+              'gcc_major': '<!(<(python) -c "import os; import subprocess; CXX=os.environ.get(\'CXX\', \'g++\'); subprocess.run([CXX, \'-dumpversion\'])")'
+            },
             # Disable the following compiler warning:
             #
             #   warning: visibility attribute not supported in this
@@ -589,7 +592,7 @@
             # out more relevant warnings.
             'cflags': [ '-Wno-attributes' ],
             'ldflags': [
-              '-Wl,-blibpath:/usr/lib:/lib:/opt/freeware/lib/pthread/ppc64',
+              '-Wl,-blibpath:/usr/lib:/lib:/opt/freeware/lib/gcc/powerpc-ibm-aix7.3.0.0/>(gcc_major)/pthread/ppc64:/opt/freeware/lib/gcc/powerpc-ibm-aix7.2.0.0/>(gcc_major)/pthread/ppc64:/opt/freeware/lib/pthread/ppc64',
             ],
           }],
         ],

doc/api/test.md

@@ -3423,9 +3423,9 @@ behaves in the same fashion as the top level [`test()`][] function.
 test('top level test', async (t) => {
   await t.test(
     'This is a subtest',
-    { only: false, skip: false, concurrency: 1, todo: false, plan: 4 },
+    { only: false, skip: false, concurrency: 1, todo: false, plan: 1 },
     (t) => {
-      assert.ok('some relevant assertion here');
+      t.assert.ok('some relevant assertion here');
     },
   );
 });