[ENH] Support for llvm 19

[0dminnimda]

Some package mamagers do not provide a way to downgrade. When trying to compile odin I get this error

$ ./build_odin.sh release-native
ERROR: Invalid LLVM version 19.1.2: must be 11, 12, 13, 14, 17 or 18

After I remove version check from the script, I get this:

In file included from src/main.cpp:88:
In file included from src/llvm_backend.cpp:19:
src/llvm_backend_debug.cpp:1099:2: error: use of undeclared identifier 'LLVMDIBuilderInsertDeclareAtEnd'; did you mean 'LLVMDIBuilderInsertDeclareRecordAtEnd'?
 1099 |         LLVMDIBuilderInsertDeclareAtEnd(m->debug_builder, storage, var_info, llvm_expr, llvm_debug_loc, block);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |         LLVMDIBuilderInsertDeclareRecordAtEnd
/data/data/com.termux/files/usr/include/llvm-c/DebugInfo.h:1300:18: note: 'LLVMDIBuilderInsertDeclareRecordAtEnd' declared here
 1300 | LLVMDbgRecordRef LLVMDIBuilderInsertDeclareRecordAtEnd(
      |                  ^
In file included from src/main.cpp:88:
In file included from src/llvm_backend.cpp:19:
src/llvm_backend_debug.cpp:1163:2: error: use of undeclared identifier 'LLVMDIBuilderInsertDeclareAtEnd'; did you mean 'LLVMDIBuilderInsertDeclareRecordAtEnd'?
 1163 |         LLVMDIBuilderInsertDeclareAtEnd(m->debug_builder, storage, var_info, llvm_expr, llvm_debug_loc, block->block);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |         LLVMDIBuilderInsertDeclareRecordAtEnd
/data/data/com.termux/files/usr/include/llvm-c/DebugInfo.h:1300:18: note: 'LLVMDIBuilderInsertDeclareRecordAtEnd' declared here
 1300 | LLVMDbgRecordRef LLVMDIBuilderInsertDeclareRecordAtEnd(
      |                  ^
In file included from src/main.cpp:88:
In file included from src/llvm_backend.cpp:23:
src/llvm_backend_expr.cpp:4597:13: error: use of undeclared identifier 'LLVMConstShl'
 4597 |                                         mask = LLVMConstShl(mask, LLVMConstInt(lit, f.bit_size, false));
      |                                                ^
src/llvm_backend_expr.cpp:4645:14: error: use of undeclared identifier 'LLVMConstShl'
 4645 |                                                 mask = LLVMConstShl(mask, LLVMConstInt(vt, mask_width, false));
      |                                                        ^

It would be nive to get odin working with llvm 19. Possibly I can work on it.

Related to termux/termux-packages#22012

[0dminnimda]

1. Replacing LLVMDIBuilderInsertDeclareAtEnd with LLVMDIBuilderInsertDeclareRecordAtEnd works just fine

2. As can be seen in release notes:

The following functions for creating constant expressions have been removed, because the underlying constant expressions are no longer supported. Instead, an instruction should be created using the LLVMBuildXYZ APIs, which will constant fold the operands if possible and create an instruction otherwise:

• LLVMConstICmp
• LLVMConstFCmp
• LLVMConstShl