Use llvm-objcopy to package Windows binaries

Fixes #793.

.github/workflows/cpp-packaging.yml

@@ -561,8 +561,8 @@ jobs:
               # MacOS: use LLVM binutils for both X64 and ARM64
               additional_flags+=(-L)
             elif [[ "${{ matrix.sdk_platform }}" == "windows" && "${variant}" == *"/x64/"* ]]; then
-              # Windows x64: force input and output target format
-              additional_flags+=(-f pe-x86-64,pe-bigobj-x86-64)
+              # Windows x64: force input and output target format and use LLVM binutils for correct objcopy (issue #793)
+              additional_flags+=(-f pe-x86-64,pe-bigobj-x86-64 -L)
             elif [[ "${{ matrix.sdk_platform }}" == "windows" && "${variant}" == *"/x86/"* ]]; then
               # Windows x86: force input and output target format
               additional_flags+=(-f pe-i386,pe-bigobj-i386)

scripts/gha/install_prereqs_desktop.py

@@ -80,9 +80,18 @@ def main():
           # sudo apt install clang-format
           utils.run_command(['apt', 'install', '-y','clang-format'], as_root=True)
       elif utils.is_mac_os():
-          # brew install protobuf
+          # brew install clang-format
           utils.run_command(['brew', 'install', 'clang-format'])
 
+    # Install llvm on linux/mac if its not installed already
+    if not utils.is_command_installed('llvm-objcopy'):
+      if utils.is_linux_os():
+          # sudo apt install llvm
+          utils.run_command(['apt', 'install', '-y','llvm'], as_root=True)
+      elif utils.is_mac_os():
+          # brew install llvm
+          utils.run_command(['brew', 'install', 'llvm'])
+
     # On Linux, if gcc-10 isn't installed install it. Then make it the default.
     if utils.is_linux_os():
       # Check if we have gcc 9 or gcc 10 as the default, if not, set gcc 10.