RFR: JDK-8302656: Missing spaces in output of -XX:+CIPrintMethodCodes

[Tobias Holenstein]

When printing bytecode and method data with `-XX:+CIPrintMethodCodes` we got some lines with missing whitespace: 
``` 
  11760bci: 1895VirtualCallData count(0) nonprofiled_count(0) entries(0) 
``` 

The reason for this is the use of `st->fill_to(6);` which fills up the stream with whitespace up to length 6. In our case we have 2 whitespaces before and then a  numbers >=1000 which already adds up to 6+ characters in the stream.

**Solution**: Always add a whitespace afterwards. Now 


  0    bci: 2    VirtualCallData    count(0) nonprofiled_count(0) entries(0)
  48   bci: 19   VirtualCallData    count(0) nonprofiled_count(0) entries(0)
  552  bci: 109  VirtualCallData    count(0) nonprofiled_count(0) entries(0)
  7320 bci: 1207 VirtualCallData    count(0) nonprofiled_count(0) entries(0)
  11760 bci: 1895 VirtualCallData count(0) nonprofiled_count(0) entries(0)

-------------

Commit messages:
 - JDK-8302656: Missing spaces in output of -XX:+CIPrintMethodCodes

Changes: https://git.openjdk.org/jdk/pull/12591/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12591&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8302656
  Stats: 4 lines in 2 files changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/12591.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12591/head:pull/12591

PR: https://git.openjdk.org/jdk/pull/12591