RFR [16] 8248170 Excessive include of compiledMethod, codeCache, javaClasses and systemDictionary

[Ioi Lam]

https://bugs.openjdk.java.net/browse/JDK-8248170
http://cr.openjdk.java.net/~iklam/jdk16/8248170-fix-includes-compiledMethod-etc.v01/

{compiledMethod, codeCache, javaClasses, systemDictionary}.hpp are 
unnecessarily included in some popular headers. This introduces 
unnecessary dependencies and slows down compile time.

slowdebug:
total number of files compiled: 264606 -> 260588 = -1.5%
total number of lines compiled: 76073364 -> 74477347 = -2.1%
size of libjvm.so (internal symbols): 234180296 bytes -> 233129904 bytes 
= -0.5%

(I got the statistics by parsing the *.d files in the build directory).

Thanks
- Ioi