[clang-format] Allow line break between template closer and right paren

[rymiel]

Summary

This allows for AlignAfterOpenBracket: BlockIndent to work correctly
when using values with type parameters.

Line breaks after any template closer was disallowed 10 years ago, in
90e51fdbab33d43e0d4f932c2d90d0b86e865664, as a fix to https://github.com/llvm/llvm-project/issues/15158.
Allowing it again, but only if preceding a specific character, seems to
work out fine.

Note that this change originally caused a test failure in FormatTestJS.NoBreakAfterAsserts,
which is why there is an explicit negative check against TT_JsTypeColon.

Given this, I'm not 100% confident in this change not producing defects,
especially in other languages, but that was the only one in the test
suite.
Perhaps additional restrictions should be used, such as requiring
BAS_BlockIndent to be set.

Fixes https://github.com/llvm/llvm-project/issues/59567

[HazardyKnusperkeks]

Maybe do not limit to JsTypeColon but all colons? What about something like f(some_template<Variable>).method()? I'd have to check where it breaks if there isn't a template in the argument, but I'd guess not before the paren.

clang/lib/Format/TokenAnnotator.cpp

4953–4958

Could you merge this?

clang/lib/Format/TokenAnnotator.cpp

bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
   if (Right.isOneOf(TT_RangeBasedForLoopColon, TT_OverloadedOperatorLParen,
                     TT_OverloadedOperator)) {
     return false;
   }
   if (Left.is(TT_RangeBasedForLoopColon))
     return true;
   if (Right.is(TT_RangeBasedForLoopColon))
     return false;
   if (Left.is(TT_TemplateCloser) && Right.is(TT_TemplateOpener))
     return true;
+  if (Left.is(TT_TemplateCloser) && Right.is(tok::r_paren) &&
+      (!Right.Next || Right.Next->isNot(TT_JsTypeColon))) {
+    return true;
+  }
   if ((Left.is(tok::greater) && Right.is(tok::greater)) ||
       (Left.is(tok::less) && Right.is(tok::less))) {
     return false;
   }
   if (Right.is(TT_BinaryOperator) &&
       Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None &&
       (Style.BreakBeforeBinaryOperators == FormatStyle::BOS_All ||
        Right.getPrecedence() != prec::Assignment)) {

clang/unittests/Format/FormatTest.cpp

TEST_F(FormatTest, AlignAfterOpenBracketBlockIndent) {
   verifyFormat("void (*functionPointer)() = nullptr;", Style);
   verifyFormat("void (*functionPointer)() = nullptr;",
                "void (\n"
                "    *functionPointer\n"
                ")\n"
                "(\n"
                ") = nullptr;",
                Style);
+
+  verifyFormat("static_assert(\n"
+               "    std::is_base_of_v<std::output_iterator_tag, Category> ||\n"
+               "    std::is_base_of_v<std::input_iterator_tag, Category>\n"
+               ");",
+               Style);
 }
 
 TEST_F(FormatTest, AlignAfterOpenBracketBlockIndentIfStatement) {
   auto Style = getLLVMStyle();
 
   verifyFormat("if (foo()) {\n"
                "  return;\n"
                "}",