packcore: add missing libraries for ubuntu

When listing shared libraries with the ldd command we have to add some
missing libraries like `libgcc_s.so.1` and `libnss_files.so.2`, they
have different paths on centos and ubuntu, we should search for them on
all possible paths.

(cherry picked from commit dbeba12e)

gpMgmt/sbin/packcore

@@ -67,8 +67,23 @@ def _getLibraryListWithLDD(binary):
     # We manually seed this with a few libraries that are missed
     # This may not be needed for all proces, but will round out the
     # postgres binary debugging
-    # TODO: Look a ways to distinguise a 32 vs. 64 bit executable
-    libraries = ['/lib64/libgcc_s.so.1', '/lib64/libnss_files.so.2', '/lib/libgcc_s.so.1', '/lib/libnss_files.so.2']
+    # TODO: Look at ways to distinguish a 32 vs. 64 bit executable
+    libraries = [
+        # on centos
+        '/lib64/libgcc_s.so.1',
+        '/lib64/libnss_files.so.2',
+        '/lib/libgcc_s.so.1',
+        '/lib/libnss_files.so.2',
+
+        # on ubuntu
+        '/lib/x86_64-linux-gnu/libgcc_s.so.1',
+        '/lib/x86_64-linux-gnu/libnss_files.so.2',
+        '/usr/lib32/libgcc_s.so.1',
+        '/lib32/libnss_files.so.2',
+        '/usr/libx32/libgcc_s.so.1',
+        '/libx32/libnss_files.so.2',
+    ]
+
     ldd_output = Popen('ldd `which postgres`', shell=True, stdout=PIPE)
     for line in ldd_output.stdout:
         match = re.search(r'(\S+) \(0x', line)