[clang-format] Avoid considering include directive as a template closer.

[curdeius]

Summary

This fixes a bug PR48891 introduced in D93839 where:

#include <stdint.h>
namespace rep {}

got formatted as

#include <stdint.h>
namespace rep {
}

[leonardchan]

LGTM. Confirmed on our end this fixes our issue. Thanks for addressing this!

[MyDeveloperDay]

LGTM

[curdeius]

@tstellar, could this be cherry-picked to 12.x branch? As noted above and discussed in D93839, this fixes PR48891 bug that introduced an unintended change in behaviour of clang-format.

clang/lib/Format/UnwrappedLineFormatter.cpp

tryFitMultipleLinesInOne(LevelIndentTracker &IndentTracker,
     if (Style.BraceWrapping.SplitEmptyRecord &&
         TheLine->Last->is(tok::l_brace) && I != AnnotatedLines.begin() &&
         I[-1]->Last) {
       const FormatToken *Previous = I[-1]->Last;
       if (Previous) {
         if (Previous->is(tok::comment))
           Previous = Previous->getPreviousNonComment();
         if (Previous) {
-          if (Previous->is(tok::greater))
+          if (Previous->is(tok::greater) && !I[-1]->InPPDirective)
             return 0;
           if (Previous->is(tok::identifier)) {
             const FormatToken *PreviousPrevious =
                 Previous->getPreviousNonComment();
             if (PreviousPrevious &&
                 PreviousPrevious->isOneOf(tok::kw_class, tok::kw_struct))
               return 0;
           }

clang/unittests/Format/FormatTest.cpp

verifyFormat("template <typename T> class rep<std::complex<T>>\n"
                "{\n"
                "  int x;\n"
                "};",
                Style);
   verifyFormat("template <typename T> class rep<std::complex<T>>\n"
                "{\n"
                "};",
                Style);
+
+  verifyFormat("#include \"stdint.h\"\n"
+               "namespace rep {}",
+               Style);
+  verifyFormat("#include <stdint.h>\n"
+               "namespace rep {}",
+               Style);
+  verifyFormat("#include <stdint.h>\n"
+               "namespace rep {}",
+               "#include <stdint.h>\n"
+               "namespace rep {\n"
+               "\n"
+               "\n"
+               "}",
+               Style);
 }
 
 TEST_F(FormatTest, SplitEmptyStruct) {
   FormatStyle Style = getLLVMStyle();
   Style.BreakBeforeBraces = FormatStyle::BS_Custom;
   Style.BraceWrapping.AfterStruct = true;
   Style.BraceWrapping.SplitEmptyRecord = false;