There seems to be no point in configuring the compiler argument per
project. This argument will be deleted soon anyway, when we remove
support for JDK 1.6 & 1.7.
Also remove `disableDeprecatedJvmTargetWarning`. It didn't have any
effect in all modules where it was applied because these modules
reassign `freeCompilerArgs` anyway, with
`-Xsuppress-deprecated-jvm-target-warning` in it.
The main reason for this change is that the current API for class
version requirements (`KmClass.versionRequirements`) makes it impossible
to support pre-1.4 metadata where this was stored incorrectly for nested
classes: with the "version requirement table" in the outer class, and
indexes into that table in nested classes. See KT-41011.
Other than this aspect, metadata of classes is basically the same in
pre-1.4 and 1.4, which means that if some kotlinx-metadata-jvm users
really need to serialize metadata of an earlier version and they don't
care about the version requirements issue, they can just use these new
bytes but write the earlier version (e.g. 1.1) to the class file.
Everything will work the same, except for the possible version
requirements issue mentioned above.
Note that metadata version 1.4 is still supported for
`KotlinModuleMetadata.Writer` though.
#KT-41011 Fixed
It turns out that `jvmTarget` and `javaHome` settings in
build.gradle.kts were changing the module settings and affected the
compilation of kotlinx-metadata-jvm sources. The correct way to use JDK
8 in tests would be to change JVM target / JDK home of the specific
KotlinCompile task via its `kotlinOptions`, but JarContentTest doesn't
need JDK 8 anyway at this moment, so simplify that instead.
With gradle > 5.0 `publish()` helper call should be done before
`noDefaultJar()` or any other artifact hacks, otherwise singing plugin doesn't sign any jars
Vyacheslav Gerasimov