Use a custom diagnostic when parsing SIL DIExpressions

Author: adrian-prantl

include/swift/AST/DiagnosticsParse.def

@@ -522,6 +522,8 @@ ERROR(sil_invalid_column_in_sil_location,none,
       "column number must be a positive integer", ())
 ERROR(sil_invalid_scope_slot,none,
       "scope number must be a positive integer ", ())
+ERROR(sil_invalid_constant,none,
+      "constant operand must be an integer literal ", ())
 ERROR(sil_scope_undeclared,none,
       "scope number %0 needs to be declared before first use", (unsigned))
 ERROR(sil_scope_redefined,none,

lib/SIL/Parser/ParseSIL.cpp

@@ -1701,8 +1701,7 @@ bool SILParser::parseSILDebugInfoExpression(SILDebugInfoExpression &DIExpr) {
             IsNegative = true;
           }
           int64_t Val;
-          // FIXME: Use the correct diagnostic
-          if (parseInteger(Val, diag::sil_invalid_scope_slot))
+          if (parseInteger(Val, diag::sil_invalid_constant))
             return true;
           if (IsNegative)
             Val = -Val;