This adds a new mode where we always build the app with the new library,
and run it with the old and new library. This is used to test backward
deployment of code that uses weak-linked symbols.
To ensure that we properly crash if we reference an undefined symbol that
is not weak linked, also pass a linker flag to bind symbols eagerly.
A resilient change should not *remove* previously-public symbols.
Note that currently, the test_superclass_properties test does not
meet this critierion, because we always emit keypath property
descriptors, even when the property is an override. Fixing this
is a larger change that I'll address in a follow-on PR, so for now
I'm just going to disable the symbol check for this one test only.
Part of <rdar://problem/40432647>.
At least test_rth.swift is checking the name of the executable
during the test, so renaming every executable to __executable in
Android will never work.
Also, during the rth tool execution, all the results from before
and after are pushed for every test. Since Android copies the
passed files without relative paths, the library files will
overwrite each other, making the test fail.
Depends on #19949 (more or less)
Most of this is just "remember to specify the inputs and outputs on
the command line, so remote-run can see them". A bit is "prefix
environment variables with '%env-'". And the last few are "yeah,
this was never going to work in a remote environment".
In the few cases where I couldn't think of anything reasonable, I just
marked the test as "UNSUPPORTED: remote_run", a new "feature".
* E101: indentation contains mixed spaces and tabs
* E111: indentation is not a multiple of four
* E128: continuation line under-indented for visual indent
* E302: expected 2 blank lines, found 1
* W191: indentation contains tabs
Before this commit:
```
$ flake8
./utils/rth:34:17: E127 continuation line over-indented for visual indent
./utils/rth:67:27: E127 continuation line over-indented for visual indent
$
```
After this commit:
```
$ flake8
$
```
