build: stop leaking AVX/AVX2 codegen into scalar/SSE2 TUs

batch_validation.cpp and plot_generation.cpp contain no SIMD intrinsics —
they only call into shabal256_avx2/sse2 via ordinary function calls. The
set_property(SOURCE ... COMPILE_OPTIONS ${AVX2_CXXFLAGS}) blocks therefore
served no purpose and let the compiler emit AVX/AVX2 anywhere in those
TUs (memset/memcpy expansion to YMM, VEX-encoded SSE, auto-vectorization).
The result was SIGILL on non-AVX2 x86-64 CPUs before the runtime
HaveAVX2() gate could fire.

Drop the three set_property blocks; keep target_compile_definitions
ENABLE_AVX2, which is just a #define and has no codegen impact. The
intrinsics-bearing TUs (shabal256_avx2.cpp, sha256_avx2.cpp) keep their
flags via src/crypto/CMakeLists.txt and are unaffected.

Fixes PoC-Consortium/bitcoin-pocx#1.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: JohnnyFFM

src/CMakeLists.txt

@@ -90,12 +90,6 @@ target_link_libraries(bitcoin_consensus
 # Enable AVX2 for PoCX batch validation if available
 if(ENABLE_POCX AND HAVE_AVX2)
   target_compile_definitions(bitcoin_consensus PRIVATE ENABLE_AVX2)
-  set_property(SOURCE pocx/consensus/batch_validation.cpp PROPERTY
-    COMPILE_OPTIONS ${AVX2_CXXFLAGS}
-  )
-  set_property(SOURCE pocx/algorithms/plot_generation.cpp PROPERTY
-    COMPILE_OPTIONS ${AVX2_CXXFLAGS}
-  )
 endif()
 # SSE2 is baseline on x86-64, no special compiler flags needed
 if(ENABLE_POCX AND CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64")

src/kernel/CMakeLists.txt

@@ -116,12 +116,6 @@ endif()
 # Enable AVX2 for PoCX batch validation if available
 if(ENABLE_POCX AND HAVE_AVX2)
   target_compile_definitions(bitcoinkernel PRIVATE ENABLE_AVX2)
-  set_property(SOURCE ../pocx/consensus/batch_validation.cpp PROPERTY
-    COMPILE_OPTIONS ${AVX2_CXXFLAGS}
-  )
-  set_property(SOURCE ../pocx/algorithms/plot_generation.cpp PROPERTY
-    COMPILE_OPTIONS ${AVX2_CXXFLAGS}
-  )
 endif()
 # SSE2 is baseline on x86-64, no special compiler flags needed
 if(ENABLE_POCX AND CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64")