[CMake] Expose backtrace symbols in Debug mode

[hcho3]

Remove -fvisibility=hidden flag when the build mode is set to Debug, to expose more symbols in the backtrace.

BEFORE:

tvm._ffi.base.TVMError: Traceback (most recent call last):
  [bt] (8) /home/ubuntu/tvm/build/libtvm.so(+0xc0497b) [0x7f51fdc3e97b]
  [bt] (7) /home/ubuntu/tvm/build/libtvm.so(+0xc0227c) [0x7f51fdc3c27c]
  [bt] (6) /home/ubuntu/tvm/build/libtvm.so(+0xc03a0d) [0x7f51fdc3da0d]
  [bt] (5) /home/ubuntu/tvm/build/libtvm.so(+0xc048a4) [0x7f51fdc3e8a4]
  [bt] (4) /home/ubuntu/tvm/build/libtvm.so(+0xc059ca) [0x7f51fdc3f9ca]
  [bt] (3) /home/ubuntu/tvm/build/libtvm.so(+0xc062c9) [0x7f51fdc402c9]
  [bt] (2) /home/ubuntu/tvm/build/libtvm.so(+0xc0688f) [0x7f51fdc4088f]
  [bt] (1) /home/ubuntu/tvm/build/libtvm.so(+0xcb2ea1) [0x7f51fdcecea1]
  [bt] (0) /home/ubuntu/tvm/build/libtvm.so(+0x47ee32) [0x7f51fd4b8e32]
  File "/home/ubuntu/tvm/src/relay/pass/quantize.cc", line 315
TVMError: Check failed: lhs->dtype == dtype (int8 vs. int32)

AFTER:

tvm._ffi.base.TVMError: Traceback (most recent call last):
  [bt] (8) /home/ubuntu/tvm/build/libtvm.so(std::_Function_handler<void (tvm::runtime::TVMArgs, tvm::runtime::TVMRetValue*), tvm::runtime::TypedPackedFunc<tvm::relay::Expr
 (tvm::relay::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeRef const&)>::AssignTypedLambda<tvm::relay::Expr (*)(tvm::relay::Call const&, tvm::Array<tvm
::relay::Expr, void> const&, tvm::NodeRef const&)>(tvm::relay::Expr (*)(tvm::relay::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeRef const&))::{lambda(
tvm::runtime::TVMArgs const&, tvm::runtime::TVMRetValue*)#1}>::_M_invoke(std::_Any_data const&, tvm::runtime::TVMArgs&&, tvm::runtime::TVMRetValue*&&)+0x4f) [0x7fdec2652b5
5]
  [bt] (7) /home/ubuntu/tvm/build/libtvm.so(tvm::runtime::TypedPackedFunc<tvm::relay::Expr (tvm::relay::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeRe
f const&)>::AssignTypedLambda<tvm::relay::Expr (*)(tvm::relay::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeRef const&)>(tvm::relay::Expr (*)(tvm::rela
y::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeRef const&))::{lambda(tvm::runtime::TVMArgs const&, tvm::runtime::TVMRetValue*)#1}::operator()(tvm::run
time::TVMArgs const&, tvm::runtime::TVMRetValue*) const+0x3a) [0x7fdec265044e]
  [bt] (6) /home/ubuntu/tvm/build/libtvm.so(void tvm::runtime::detail::unpack_call<tvm::relay::Expr, 3, tvm::relay::Expr (*)(tvm::relay::Call const&, tvm::Array<tvm::relay
::Expr, void> const&, tvm::NodeRef const&)>(tvm::relay::Expr (* const&)(tvm::relay::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeRef const&), tvm::runt
ime::TVMArgs const&, tvm::runtime::TVMRetValue*)+0x2b) [0x7fdec2651be7]
  [bt] (5) /home/ubuntu/tvm/build/libtvm.so(void tvm::runtime::detail::unpack_call_dispatcher<tvm::relay::Expr, 3, 0, tvm::relay::Expr (*)(tvm::relay::Call const&, tvm::Ar
ray<tvm::relay::Expr, void> const&, tvm::NodeRef const&)>::run<>(tvm::relay::Expr (* const&)(tvm::relay::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeR
ef const&), tvm::runtime::TVMArgs const&, tvm::runtime::TVMRetValue*)+0x5a) [0x7fdec2652a7e]
  [bt] (4) /home/ubuntu/tvm/build/libtvm.so(void tvm::runtime::detail::unpack_call_dispatcher<tvm::relay::Expr, 2, 1, tvm::relay::Expr (*)(tvm::relay::Call const&, tvm::Ar
ray<tvm::relay::Expr, void> const&, tvm::NodeRef const&)>::run<tvm::runtime::TVMArgValue>(tvm::relay::Expr (* const&)(tvm::relay::Call const&, tvm::Array<tvm::relay::Expr,
 void> const&, tvm::NodeRef const&), tvm::runtime::TVMArgs const&, tvm::runtime::TVMRetValue*, tvm::runtime::TVMArgValue&&)+0x73) [0x7fdec2653ba4]
  [bt] (3) /home/ubuntu/tvm/build/libtvm.so(void tvm::runtime::detail::unpack_call_dispatcher<tvm::relay::Expr, 1, 2, tvm::relay::Expr (*)(tvm::relay::Call const&, tvm::Ar
ray<tvm::relay::Expr, void> const&, tvm::NodeRef const&)>::run<tvm::runtime::TVMArgValue, tvm::runtime::TVMArgValue>(tvm::relay::Expr (* const&)(tvm::relay::Call const&, t
vm::Array<tvm::relay::Expr, void> const&, tvm::NodeRef const&), tvm::runtime::TVMArgs const&, tvm::runtime::TVMRetValue*, tvm::runtime::TVMArgValue&&, tvm::runtime::TVMArg
Value&&)+0x8a) [0x7fdec26544a3]
  [bt] (2) /home/ubuntu/tvm/build/libtvm.so(void tvm::runtime::detail::unpack_call_dispatcher<tvm::relay::Expr, 0, 3, tvm::relay::Expr (*)(tvm::relay::Call const&, tvm::Ar
ray<tvm::relay::Expr, void> const&, tvm::NodeRef const&)>::run<tvm::runtime::TVMArgValue, tvm::runtime::TVMArgValue, tvm::runtime::TVMArgValue>(tvm::relay::Expr (* const&)
(tvm::relay::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeRef const&), tvm::runtime::TVMArgs const&, tvm::runtime::TVMRetValue*, tvm::runtime::TVMArgVa
lue&&, tvm::runtime::TVMArgValue&&, tvm::runtime::TVMArgValue&&)+0xa6) [0x7fdec2654a69]
  [bt] (1) /home/ubuntu/tvm/build/libtvm.so(tvm::relay::quantize::MulRealize(tvm::relay::Call const&, tvm::Array<tvm::relay::Expr, void> const&, tvm::NodeRef const&)+0x431
) [0x7fdec270177b]
  [bt] (0) /home/ubuntu/tvm/build/libtvm.so(dmlc::LogMessageFatal::~LogMessageFatal()+0x4a) [0x7fdec1ec9786]
  File "/home/ubuntu/tvm/src/relay/pass/quantize.cc", line 315
TVMError: Check failed: lhs->dtype == dtype (int8 vs. int32)

[tqchen]

Looks good. One thing that I noticed is that maybe we need to add force inline macro(like those in mshadow) to many of the unpack call dispatcher so they are properly inlined