[clang-format] Support of TableGen value annotations. (#80299)

This implements the annotation of the values in TableGen.
The main changes are,

- parseTableGenValue(), the simplified parser method for the syntax of
values.
- modified consumeToken() to parseTableGenValue in 'if', 'assert' and
after '='.
- modified parseParens() to call parseTableGenValue inside.
- modified parseSquare() to to call parseTableGenValue inside, with
skipping separator tokens.
- modified parseAngle() to call parseTableGenValue inside, with skipping
separator tokens.

Author: hnakamura5

clang/lib/Format/FormatToken.h

@@ -150,7 +150,17 @@ namespace format {
   TYPE(StructuredBindingLSquare)                                               \
   TYPE(TableGenBangOperator)                                                   \
   TYPE(TableGenCondOperator)                                                   \
+  TYPE(TableGenCondOperatorColon)                                              \
+  TYPE(TableGenCondOperatorComma)                                              \
+  TYPE(TableGenDAGArgCloser)                                                   \
+  TYPE(TableGenDAGArgListColon)                                                \
+  TYPE(TableGenDAGArgListComma)                                                \
+  TYPE(TableGenDAGArgOpener)                                                   \
+  TYPE(TableGenListCloser)                                                     \
+  TYPE(TableGenListOpener)                                                     \
   TYPE(TableGenMultiLineString)                                                \
+  TYPE(TableGenTrailingPasteOperator)                                          \
+  TYPE(TableGenValueSuffix)                                                    \
   TYPE(TemplateCloser)                                                         \
   TYPE(TemplateOpener)                                                         \
   TYPE(TemplateString)                                                         \

clang/lib/Format/FormatTokenLexer.cpp

@@ -812,7 +812,7 @@ void FormatTokenLexer::handleTableGenMultilineString() {
   auto CloseOffset = Lex->getBuffer().find("}]", OpenOffset);
   if (CloseOffset == StringRef::npos)
     return;
-  auto Text = Lex->getBuffer().substr(OpenOffset, CloseOffset + 2);
+  auto Text = Lex->getBuffer().substr(OpenOffset, CloseOffset - OpenOffset + 2);
   MultiLineString->TokenText = Text;
   resetLexer(SourceMgr.getFileOffset(
       Lex->getSourceLocation(Lex->getBufferLocation() - 2 + Text.size())));