[llvm] [llvm] fix mustache template whitespace (PR #153724)

[via llvm-commits]

mdenson wrote:

any thoughts? unless you think otherwise, i can add the now (somewhat) passing spec test https://github.com/mustache/spec/blob/master/specs/partials.yml#L89-L107 to the unit tests (with the exchange of {{& }} for {{{ }}}) at https://github.com/llvm/llvm-project/blob/main/llvm/unittests/Support/MustacheTest.cpp and we could close the issue.

if there are other mustache features we care about and want to implement (such as {{{ }}}), i can give that a shot in another pr




https://github.com/llvm/llvm-project/pull/153724