Update shaderc.cpp
Update shaderc.cpp

Fix for crash in release mode when compiling a shader with incorrect input attributes.

bkaradzic/bgfx,attilaz/bgfx,fluffyfreak/bgfx,jpcy/bgfx,fluffyfreak/bgfx,emoon/bgfx,attilaz/bgfx,jdryg/bgfx,LWJGL-CI/bgfx,bkaradzic/bgfx,jpcy/bgfx,jdryg/bgfx,fluffyfreak/bgfx,MikePopoloski/bgfx,mendsley/bgfx,MikePopoloski/bgfx,emoon/bgfx,LWJGL-CI/bgfx,MikePopoloski/bgfx,mendsley/bgfx,attilaz/bgfx,jdryg/bgfx,mendsley/bgfx,bkaradzic/bgfx,fluffyfreak/bgfx,jpcy/bgfx,emoon/bgfx,bkaradzic/bgfx,jdryg/bgfx,LWJGL-CI/bgfx,LWJGL-CI/bgfx,jpcy/bgfx