Bug ID: JDK-8310027 Fix -Wconversion warnings in nmethod and compiledMethod related code

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JDK 22
22 b03Fixed

The nmethod.hpp and compiledMethod.hpp files have implicit address to int conversions for returning offsets and sizes.Since hopefully an nmethod size should never exceed 32 bits, this seems safe to simply add explicit casts.

The question is which is better:

+  int oops_size         () const                  { return int((address)  oops_end         () - (address)  oops_begin         ()); }

Or

 +  int oops_size         () const                  { return (int)((address)  oops_end         () - (address)  oops_begin         ()); }

It doesn't seem like we should slow down compilation or add noise to make these

+  int oops_size         () const                  { return checked_cast<int>((address)  oops_end         () - (address)  oops_begin         ()); }

Compiling with -Wconversion and not -Werror gives these counts for warnings:

5523 /scratch/cphillim/hg/21more-conversion/src/hotspot/share/code/nmethod.hpp
5523 /scratch/cphillim/hg/21more-conversion/src/hotspot/share/code/compiledMethod.hpp
4150 /scratch/cphillim/hg/21more-conversion/src/hotspot/share/code/relocInfo.hpp

Changeset: e1906e76 Author: Coleen Phillimore <coleenp@openjdk.org> Date: 2023-06-20 13:35:11 +0000 URL: https://git.openjdk.org/jdk/commit/e1906e76412fa506cf72447dcb9adc896b92ae81

20-06-2023

A pull request was submitted for review. URL: https://git.openjdk.org/jdk/pull/14505 Date: 2023-06-15 22:49:36 +0000

16-06-2023

ILW = Conversion warnings in code (harmless), no issue observed, no workaround = MLH = P4

15-06-2023

Relates :	JDK-8177482 - Prepare Compiler code for -Wconversion
Relates :	JDK-8177481 - Prepare Runtime code for -Wconversion