Enable dynamic wasm build for git and update test runner

[vidyalakshmir]

Closes #101
This PR introduces the ability to compile git as a Position Independent Executable (PIE) that dynamically links its dependencies at runtime in the lind-wasm environment. It also updates our test harness to successfully execute these dynamic builds by preloading the required shared libraries.

Shared libraries that git depends on:

• openssl (libssl.so and libcrypto.so)
• zlib (libz.so)
• libc

1. Build Script Updates (git)

• Compiler Flags: Conditionally injects -fPIC into CFLAGS.
• Linker Flags: Splits standard static linking from dynamic linking. Dynamic builds now include -Wl,-pie, -Wl,--shared-memory, and --unresolved-symbols=import-dynamic.
• CRT Objects: Ensures the required Lind objects (set_stack_pointer.o, crt1_shared.o, lind_utils.o) are linked into the dynamic executable.
• Wasm Optimization: Branches wasm-opt to include --enable-bulk-memory and --enable-threads, followed by add-export-tool to explicitly expose relocation and stack pointer symbols to the host environment.

Test Runner Updates

• Runtime Preloading: Updated the test execution wrapper. When LIND_DYLINK=1, the test suite now runs lind_run with the necessary --preload env=... arguments. This resolves the unknown import errors by ensuring the Wasm runtime populates the env namespace with our shared dependencies before executing git.cwasm.

How to Test

Test Static Path:

• make git
• APP= git make test

Test Dynamic Path:

• LIND_DYLINK=1 make git
• LIND_DYLINK=1 APP= git make test
  (This requires the updates from this PR which does dynamic compilation of libraries)