bound Int coercion before expanding BigDecimal to BigInteger - #4495

variable coercion hands the raw value straight to Coercing.parseValue, so an Int-typed variable that arrives as a BigDecimal (gson, or jackson with USE_BIG_DECIMAL_FOR_FLOATS) reaches GraphqlIntCoercing.convertParseValueImpl.

new BigDecimal("1E50000000").toBigIntegerExact()   // ~14s, 166M-bit BigInteger

toBigIntegerExact() runs before the INT_MIN/INT_MAX range check in parseValueImpl, so an 11-byte value forces a ~50M digit BigInteger to be built only to then be rejected as out of range. bigger exponents scale into minutes and gigabytes before BigInteger reaches its own size limit. the literal path is capped at 100 numeric chars by the parser; the variable path has no such cap.

decide out-of-range from the decimal scale/precision rather than expanding first: an integer part with more than 10 digits cannot fit an Int, so the existing Int.outsideRange error is raised there. BigDecimal.intValueExact() already short-circuits the same way, which is why the serialize path and the Float/Boolean/ID coercers are not affected.