67f4e9c522 Include core_io.h from core_read.cpp (practicalswift)
eca9767673 Make reasoning about dependencies easier by not including unused dependencies (practicalswift)
Pull request description:
Make reasoning about dependencies easier by not including unused dependencies.
Please note that the removed headers are _not_ "transitively included" by other still included headers. Thus the removals are real.
As an added bonus this change means less work for the preprocessor/compiler. At least 51 393 lines of code no longer needs to be processed:
```
$ git diff -u HEAD~1 | grep -E '^\-#include ' | cut -f2 -d"<" | cut -f1 -d">" | \
sed 's%^%src/%g' | xargs cat | wc -l
51393
```
Note that 51 393 is the lower bound: the real number is likely much higher when taking into account transitively included headers :-)
ACKs for commit 67f4e9:
Tree-SHA512: 0c8868aac59813f099ce53d5307eed7962dd6f2ff3546768ef9e5c4508b87f8210f1a22c7e826c3c06bebbf28bdbfcf1628ed354c2d0fdb9a31a42cefb8fdf13