Make GrGLShaderBuilder check whether GrEffect advertised that it would require the dst color or frag

include/gpu/GrConfig.h

Index: include/gpu/GrConfig.h
diff --git a/include/gpu/GrConfig.h b/include/gpu/GrConfig.h
index 94c65d84a46639290d25ed041cc5dafc7559f6b9..95e518ab75a87b74a18ed3d20fe73b92c05932c0 100644
--- a/include/gpu/GrConfig.h
+++ b/include/gpu/GrConfig.h
@@ -280,10 +280,13 @@ typedef unsigned __int64 uint64_t;
 #define GrAlwaysAssert(COND) GR_ALWAYSASSERT(COND)
 
 /**
- * Crash from unrecoverable condition, optionally with a message.
+ * Crash from unrecoverable condition, optionally with a message. The debug variants only
+ * crash in a debug build. The message versions print the message regardless of release vs debug.
  */
 inline void GrCrash() { GrAlwaysAssert(false); }
 inline void GrCrash(const char* msg) { GrPrintf(msg); GrAlwaysAssert(false); }
+inline void GrDebugCrash() { GrAssert(false); }
+inline void GrDebugCrash(const char* msg) { GrPrintf(msg); GrAssert(false); }
 
 /**
  *  GR_DEBUGCODE compiles the code X in debug builds only