[9] RFR (S): 8058291: Missing some checks during parameter validation

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8058291/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8058291

8057656 & 8050166 changes accidentally removed some checks during 
argument validation in MHs.dropArguments() and 
MHs.explicitCastArguments(). The fix is to restore them.

Testing: jck (api/java_lang/invoke), jdk/java/lang/invoke, 
jdk/java/util/streams w/ "-ea -esa" and COMPILE_THRESHOLD={0,30}

Thanks!

Best regards,
Vladimir Ivanov