[WebAssembly] Add WebAssembly to LLVM_ALL_TARGETS

Summary:
After fixing memory leaks in rL343362 and rL343733 the sanitizer builds are
clean and we should be good to build by default again.

Differential Revision: https://reviews.llvm.org/D52850

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343746 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed