AArch64: Clean up code models by removing unused definitions.
This commit simplifies AArch64 code model handling by removing unused code model definitions, without changing generated code.
Several unused code model definitions (AARCH64_CMODEL_TINY_PIC, AARCH64_CMODEL_SMALL_PIC, and AARCH64_CMODEL_SMALL_SPIC) were removed, along with related code, to simplify the AArch64 code model implementation. This change does not affect the generated code, but reduces code complexity and potential maintenance overhead.
In Details
This commit cleans up aarch64.h, aarch64.cc, aarch64-c.cc, and aarch64-opts.h by removing unused code model definitions. The removed definitions are AARCH64_CMODEL_TINY_PIC, AARCH64_CMODEL_SMALL_PIC, and AARCH64_CMODEL_SMALL_SPIC. This simplifies the code without changing code generation.
For Context
This commit focuses on internal code cleanup for the AArch64 architecture in GCC. It removes several definitions related to code models that were no longer being used. Code models define how the compiler generates position-independent code (PIC), which is important for security and shared libraries. Removing dead code improves maintainability.