[Go / ASAN] Disable Go bindings for ASAN tests.

Go binding tests fail under ASAN with the error at the bottom of this
commit message. The reason the buildbots are not currently always
failing on this test is that they selectively disable the bindings due
to a Go binary not being present on their system.

This change should allow users to build an asan-bootstrapped compiler
and run asan-ified unit tests locally, similar to the way that
sanitizer-* buildbots do.

The error is:
```
FAIL: LLVM :: Bindings/Go/go.test (7050 of 30112)
******************** TEST 'LLVM :: Bindings/Go/go.test' FAILED ********************
Script:
--
: 'RUN: at line 1';   /usr/local/google/home/mitchp/llvm-build/asan/sanitized-clang/bin/llvm-go go=/usr/lib/google-golang/bin/go test llvm.org/llvm/bindings/go/llvm
--
Exit Code: 1

Command Output (stdout):
--
FAIL	llvm.org/llvm/bindings/go/llvm [build failed]

--
Command Output (stderr):
--
ld.lld: error: undefined symbol: std::allocator<char>::allocator()
>>> referenced by Instrumentati...