Add warning on some cases of integer literal coercion

Fix misisng warnings on:

int x3 = 18446744073709551615;
int x4 = 0xFFFFFFFFFFFFFFFF;

Author: zlatinski

source/slang/slang-parser.cpp

@@ -6897,7 +6897,7 @@ static IntegerLiteralValue _fixIntegerLiteral(
         // If the masked value is 0 or equal to the mask, we 'assume' no information is
         // lost
         // This allows for example -1u, to give 0xffffffff
-        // It also means 0xfffffffffffffffffu will give 0xffffffff, without a warning.
+        // It also means 0xffffffffffffffffu will give 0xffffffff, without a warning.
         if ((!(maskedValue == 0 || maskedValue == mask)) && sink && token)
         {
             // Output a warning that number has been altered
@@ -6954,16 +6954,10 @@ static BaseType _determineNonSuffixedIntegerLiteralType(
     {
         baseType = BaseType::UInt64;
 
-        if (isDecimalBase)
+        // Emit warning if the value is too large for signed 64-bit, regardless of base
+        // This fixes the inconsistency between decimal and hex literals
+        if (sink && token)
         {
-            // There is an edge case here where 9223372036854775808 or INT64_MAX + 1
-            // brings us here, but the complete literal is -9223372036854775808 or INT64_MIN and is
-            // valid. Unfortunately because the lexer handles the negative(-) part of the literal
-            // separately it is impossible to know whether the literal has a negative sign or not.
-            // We emit the warning and initially process it as a uint64 anyways, and the negative
-            // sign will be properly parsed and the value will still be properly stored as a
-            // negative INT64_MIN.
-
             // Decimal integer is too large to be represented as signed.
             // Output warning that it is represented as unsigned instead.
             sink->diagnose(*token, Diagnostics::integerLiteralTooLarge);