clang-format: [JS] Fix templated parameter default values.

Parameters can have templated types and default values (= ...), which is
another location in which a template closer should be followed by
whitespace.

Patch by Martin Probst, thank you.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236382 91177308-0d34-0410-b5e6-96231b3b80d8