GHS: Enable language-dependent generator expressions

Add `Green Hills MULTI` to the list of generators checked for the
`COMPILE_LANGUAGE`, `COMPILE_LANG_AND_ID`, `LINK_LANGUAGE`, and
`LINK_LANG_AND_ID` generator expressions, since these are supported by
the generator.

Fixes: #24262

Source/cmGeneratorExpressionNode.cxx

@@ -1468,7 +1468,8 @@ static const struct CompileLanguageNode : public cmGeneratorExpressionNode
         genName.find("Ninja") == std::string::npos &&
         genName.find("Visual Studio") == std::string::npos &&
         genName.find("Xcode") == std::string::npos &&
-        genName.find("Watcom WMake") == std::string::npos) {
+        genName.find("Watcom WMake") == std::string::npos &&
+        genName.find("Green Hills MULTI") == std::string::npos) {
       reportError(context, content->GetOriginalExpression(),
                   "$<COMPILE_LANGUAGE:...> not supported for this generator.");
       return std::string();
@@ -1516,7 +1517,8 @@ static const struct CompileLanguageAndIdNode : public cmGeneratorExpressionNode
         genName.find("Ninja") == std::string::npos &&
         genName.find("Visual Studio") == std::string::npos &&
         genName.find("Xcode") == std::string::npos &&
-        genName.find("Watcom WMake") == std::string::npos) {
+        genName.find("Watcom WMake") == std::string::npos &&
+        genName.find("Green Hills MULTI") == std::string::npos) {
       reportError(
         context, content->GetOriginalExpression(),
         "$<COMPILE_LANG_AND_ID:lang,id> not supported for this generator.");
@@ -1569,7 +1571,8 @@ static const struct LinkLanguageNode : public cmGeneratorExpressionNode
         genName.find("Ninja") == std::string::npos &&
         genName.find("Visual Studio") == std::string::npos &&
         genName.find("Xcode") == std::string::npos &&
-        genName.find("Watcom WMake") == std::string::npos) {
+        genName.find("Watcom WMake") == std::string::npos &&
+        genName.find("Green Hills MULTI") == std::string::npos) {
       reportError(context, content->GetOriginalExpression(),
                   "$<LINK_LANGUAGE:...> not supported for this generator.");
       return std::string();
@@ -1658,7 +1661,8 @@ static const struct LinkLanguageAndIdNode : public cmGeneratorExpressionNode
         genName.find("Ninja") == std::string::npos &&
         genName.find("Visual Studio") == std::string::npos &&
         genName.find("Xcode") == std::string::npos &&
-        genName.find("Watcom WMake") == std::string::npos) {
+        genName.find("Watcom WMake") == std::string::npos &&
+        genName.find("Green Hills MULTI") == std::string::npos) {
       reportError(
         context, content->GetOriginalExpression(),
         "$<LINK_LANG_AND_ID:lang,id> not supported for this generator.");