byte code instructions can fit in a byte

This isn't particularly important.  It just struck me that if we're
going to be byte-thrifty, might as well go all the way.

Change-Id: I4d137731ac06643c50e6bc66cc4654abad732cea
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/310325
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/src/sksl/SkSLByteCodeGenerator.cpp b/src/sksl/SkSLByteCodeGenerator.cpp
index 9f6148c..e46cca9 100644
--- a/src/sksl/SkSLByteCodeGenerator.cpp
+++ b/src/sksl/SkSLByteCodeGenerator.cpp
@@ -633,7 +633,7 @@
         case ByteCodeInstruction::kMaskBlend: this->exitCondition();  break;
         default: /* Do nothing */ break;
     }
-    this->write16((uint16_t)i);
+    this->write8((uint8_t)i);
     fStackCount += StackUsage(i, count);
     fMaxStackCount = std::max(fMaxStackCount, fStackCount);