Add QL_EXPORT patches for Gaussian copula and primitive polynomials

[fumitoh]

Summary

Extended the QuantLib DLL build script to apply two additional patches for proper symbol export annotations, and improved build logging and error reporting.

Key Changes

• Added two new export patches to enable DLL builds:

  • Patch 6: gaussiancopulapolicy.hpp - Annotate static const members (density_ and cumulative_) with QL_EXPORT
  • Patch 7: primitivepolynomials.hpp - Annotate extern array (PrimitivePolynomials) with QL_EXPORT and inject qldefines.hpp include if missing

• Improved build process:

  • Split monolithic build into separate library and test suite targets with individual logging
  • Added per-target build logs (build-library.log, build-testsuite.log) for better diagnostics
  • Enhanced error reporting to display last 80 lines of failed build logs inline
  • Made test suite build conditional on $BuildTests parameter

• Enhanced CI/CD error diagnostics:

  • Added GitHub Actions step to display build error logs on failure
  • Shows last 100 lines of available build logs for troubleshooting

• Minor fixes:

  • Updated test executable filter from ql_test_suite.exe to quantlib-test-suite.exe to match actual output name

Implementation Details

The new patches follow the same pattern as existing ones, using PowerShell string replacement to inject QL_EXPORT annotations. The primitivepolynomials.hpp patch includes a check to avoid duplicate includes of qldefines.hpp.

https://claude.ai/code/session_01Pe2NhovoMN1DaU6vjJ1gjj