[jdk18] RFR: 8272058: 25 Null pointer dereference defect groups in 4 files [v3]

[Daniel D.Daugherty]

On Tue, 4 Jan 2022 23:16:47 GMT, Daniel D. Daugherty <dcubed at openjdk.org> wrote:

>> A small refactoring to resolve a Parfait complaint about the return value from
>> `MacroAssembler::target_addr_for_insn(address insn_addr, unsigned insn)`
>> on AARCH64. The logic that supports returning `nullptr` as the target addr for
>> a particular instruction is moved from
>> `MacroAssembler::target_addr_for_insn(address insn_addr, unsigned insn)` to
>> `MacroAssembler::target_addr_for_insn_allow_null_ret(address insn_addr, unsigned insn)`.
>> A couple of `target_addr_for_insn()` call sites that can tolerate a `nullptr` are
>> converted to use `target_addr_for_insn_allow_null_ret()`.
>> 
>> This fix has been tested with Mach5 Tier[1-3].
>
> Daniel D. Daugherty has updated the pull request incrementally with one additional commit since the last revision:
> 
>   bulasevich CR - use NativeInstruction::is_ldrw_to_zr() instead of raw constants.

@bulasevich - Please re-review this PR. The JDK18 RDP2 cut off is next week (01.20) and
I would like to have this PR integrated before then.

@theRealAph - Since I'm changing code that you integrated, I would prefer to hear from
you on this PR. Please review these changes soon. The JDK18 RDP2 cut off is next week
(01.20) and I would like to have this PR integrated before then.

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PR: https://git.openjdk.java.net/jdk18/pull/51