Pre-compiled .syso files missing .note.GNU-stack section causing linker warnings

Description

When using hashtree as a Go dependency, the linker emits warnings about missing .note.GNU-stack sections:

/usr/bin/ld: warning: sha256_shani.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker

Root Cause

The pre-compiled .syso files in the repository are outdated and don't include the .note.GNU-stack section, even though the assembly source files (.S) have been properly updated with this section.

Analysis

• All assembly source files in src/ correctly include .section .note.GNU-stack,"",@progbits for Linux builds
• The pre-compiled hashtree_amd64.syso contains object files without this section
• Go uses the .syso files directly during builds, not the source assembly files

Reproduction

1. Import hashtree in a Go project
2. Run go build
3. Observe linker warnings for each assembly object file

Solution

Rebuild all .syso files from current sources:

make go_bindings
# For platform-specific files:
mv hashtree.syso hashtree_amd64.syso

Impact

• Current: Linker warnings on every build
• Future: Build failures when linkers remove support for executable stacks
• Security: Potential security implications from executable stack

Suggested Fix

Update the build process to regenerate all platform-specific .syso files with current toolchain and commit the updated files.

issue description powered by claude, but verified and tested manually :)

Start with the assembly sources in src/ and the committed platform-specific .syso files, especially hashtree_amd64.syso. Run make go_bindings using the current sources, rename the generated file as described, and regenerate the other platform-specific files. Verify that a Go project importing hashtree builds without the missing .note.GNU-stack linker warnings.