Fix memory leak in slang.dll about slang HOT 2 OPEN

$ build/Debug/bin/slangc.exe
Detected memory leaks!
Dumping objects ->
{1319712} normal block at 0x0000021ACE6BE010, 48 bytes long.
 Data: <`\&             > 60 5C 26 C4 1A 02 00 00 00 00 00 00 00 00 00 00
{3949} normal block at 0x0000021AC4265C60, 48 bytes long.
 Data: <          k     > 00 00 00 00 00 00 00 00 10 E0 6B CE 1A 02 00 00
{3948} normal block at 0x0000021AC425F420, 32 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 00 10 00 00 00 00 00 00
{3947} normal block at 0x0000021AC4201C50, 1024 bytes long.
 Data: <                > CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD
{3921} normal block at 0x0000021AC420B4C0, 904 bytes long.
 Data: <X a             > 58 D1 61 F5 FA 7F 00 00 01 00 00 00 00 00 00 00
{234} normal block at 0x0000021AC41DBED0, 1024 bytes long.
 Data: < 7              > 80 37 92 F5 FA 7F 00 00 D4 A6 A7 F5 FA 7F 00 00
{215} normal block at 0x0000021AC41DBA90, 1024 bytes long.
 Data: <                > 10 AC 91 F5 FA 7F 00 00 C0 BE A7 F5 FA 7F 00 00
{200} normal block at 0x0000021AC41DB650, 1024 bytes long.
 Data: <                > FC A6 91 F5 FA 7F 00 00 B4 A6 A7 F5 FA 7F 00 00
{190} normal block at 0x0000021AC41DB210, 1024 bytes long.
 Data: <                > E0 A1 91 F5 FA 7F 00 00 D0 A6 A7 F5 FA 7F 00 00
{169} normal block at 0x0000021AC41DADD0, 1024 bytes long.
 Data: <                > 90 9B 91 F5 FA 7F 00 00 B4 A6 A7 F5 FA 7F 00 00
{168} normal block at 0x0000021AC41DAB80, 528 bytes long.
 Data: <                > 00 00 00 00 00 00 00 00 90 AB 1D C4 1A 02 00 00
{163} normal block at 0x0000021AC41BF030, 128 bytes long.
 Data: <                > 00 00 00 00 00 00 00 FC FF 00 00 00 00 00 00 00
{161} normal block at 0x0000021AC41BF7B0, 128 bytes long.
 Data: <                > FC 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Object dump complete.