bionic: linker-unit-tests: Add crt_pad_segment tests

Test crt_pad_segment note parsing.

Test: atest -c linker-unit-tests
Bug: 316403210
Bug: 300367402
Bug: 307803052
Bug: 312550202
Change-Id: I0a7db8113a8b1df72696906bdd48a6ab6b6715f7
diff --git a/linker/testdata/crt_pad_segment_disabled.S b/linker/testdata/crt_pad_segment_disabled.S
new file mode 100644
index 0000000..cc2d266
--- /dev/null
+++ b/linker/testdata/crt_pad_segment_disabled.S
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm_note.h>
+
+  .section ".note.android.pad_segment", "a", %note
+  .balign 4
+  .long 1f - 0f                       // int32_t namesz
+  .long 3f - 2f                       // int32_t descsz
+  .long NT_ANDROID_TYPE_PAD_SEGMENT   // int32_t type
+0:
+  .asciz "Android"                    // char name[]
+1:
+  .balign 2
+2:
+  .long 0    // Disabled
+3:
+  .balign 2