math/flann: fix build on GCC architectures

Last addition to files/patch-src_cpp_CMakeLists.txt breaks build.

Also require newer GCC.

PR:		249152
Approved by:	yuri (maintainer)

math/flann/Makefile

@@ -15,7 +15,7 @@ LIB_DEPENDS=	libhdf5.so:science/hdf5 \
 		liblz4.so:archivers/liblz4 \
 		libsz.so:science/szip
 
-USES=		cmake localbase:ldflags pkgconfig
+USES=		cmake compiler:c++11-lang localbase:ldflags pkgconfig
 USE_GITHUB=	yes
 GH_ACCOUNT=	mariusmuja
 USE_LDCONFIG=	yes

math/flann/files/patch-src_cpp_CMakeLists.txt

@@ -1,6 +1,6 @@
 --- src/cpp/CMakeLists.txt.orig	2019-04-07 03:21:23 UTC
 +++ src/cpp/CMakeLists.txt
-@@ -25,11 +25,11 @@ if (BUILD_CUDA_LIB)
+@@ -25,6 +25,6 @@ if (BUILD_CUDA_LIB)
      else()
  	    set(CUDA_NVCC_FLAGS "${CUDA_NVCC_FLAGS};" )
      endif()
@@ -8,9 +8,3 @@
 +    cuda_add_library(flann_cuda_s SHARED ${CU_SOURCES})
      set_property(TARGET flann_cuda_s PROPERTY COMPILE_DEFINITIONS FLANN_STATIC)
  endif()
- 
--if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_COMPILER_IS_GNUCC)
-+if(CMAKE_SYSTEM_NAME MATCHES "Linux|FreeBSD|DragonFly" AND CMAKE_COMPILER_IS_GNUCC)
-     add_library(flann_cpp SHARED "")
-     set_target_properties(flann_cpp PROPERTIES LINKER_LANGUAGE CXX)
-     target_link_libraries(flann_cpp -Wl,-whole-archive flann_cpp_s -Wl,-no-whole-archive)