[JDK-8388696](https://bugs.openjdk.org/browse/JDK-8388696) (PR #31999) has changed SA code to show error message if DWARF parser encounts unsupported DWARF instructions. This caused a new error in TestJhsdbJstackMixedWithXComp.java#xcomp. See JBS for details.
This PR updates to return the result from `DwarfParser::parse_dwarf_instructions` - `false` if DWARF parser failed such as unknown instruction. `DW_CFA_def_cfa_expression` is one of cases of failure because SA does not support it. However `DW_CFA_def_cfa_expression` might be set for signal trampoline such as `__restore_rt` on AMD64. Thus this PR ignores the failure in `DwarfParser::parse_dwarf_instructions` if PC points signal trampoline. This PR passed serviceability/sa tests on both AMD64 and AArch64 Linux. --------- - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - 8391940: Test serviceability/sa/TestJhsdbJstackMixedWithXComp.java#xcomp failed: ERROR: DWARF: Unknown opcode: 0xf Changes: https://git.openjdk.org/jdk/pull/32777/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=32777&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8391940 Stats: 28 lines in 3 files changed: 18 ins; 1 del; 9 mod Patch: https://git.openjdk.org/jdk/pull/32777.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/32777/head:pull/32777 PR: https://git.openjdk.org/jdk/pull/32777
