[Hexagon] Allow undefined symbols in libtvm_runtime.so on Hexagon (ap…

…ache#9024)

The shared library libtvm_runtime.so (or any other shared library built
for Hexagon) will not contain definitions of symbols from libc. To avoid
undefined symbol errors, turn that check off when building shared libs
for Hexagon.

CMakeLists.txt

@@ -322,6 +322,8 @@ if(BUILD_FOR_HEXAGON)
   # static one.
   if(NOT BUILD_STATIC_RUNTIME)
     list(APPEND RUNTIME_SRCS src/runtime/hexagon/hexagon_posix.cc)
+    # Allow undefined symbols (there will be some from libc).
+    set(TVM_NO_UNDEFINED_SYMBOLS "")
   endif()
 
   add_definitions(-D_MACH_I32=int)