Gas: Extract SEH shared helpers into separate file
SEH helpers are now in a separate shared file for reuse by the SEH implementation on AArch64.
SEH (Structured Exception Handling) helpers were moved to a separate shared file to be reused by the SEH implementation on AArch64. This change facilitates code sharing and reduces redundancy between different architectures. The shared helpers are used for handling .pdata and .xdata COFF object file formats.
In Details
This commit refactors the gas assembler's (gas) support for SEH by extracting common helper functions from gas/config/obj-coff-seh.c into a new file, gas/config/obj-coff-seh-shared.c. This prepares the ground for AArch64 SEH support, avoiding code duplication. The affected functions deal with managing the .pdata and .xdata sections in COFF object files.
For Context
Structured Exception Handling (SEH) is a mechanism for handling exceptions (errors) in a structured manner. The GNU Assembler (gas) needs to support SEH when generating object files for certain platforms. This change reorganizes the assembler's code to allow SEH support to be more easily shared across different processor architectures, specifically preparing for AArch64 support.