runtime(compiler): include a Java Maven compiler plugin

@Konfekt suggested adding this [1]; I confirmed that both source
repositories have permissive licenses [2], [3] that permit copying the
code (at least where the compiler scripts are concerned).

[1]: benknoble/Dotfiles@570b100
[2]: https://github.com/JalaiAmitahl/maven-compiler.vim
[3]: mikelue/vim-maven-plugin#13

closes: #16041

Signed-off-by: D. Ben Knoble <ben.knoble+github@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

Author: benknoble

runtime/compiler/maven.vim

@@ -0,0 +1,40 @@
+" Vim compiler file
+" Compiler:	Maven
+" Maintainer:	D. Ben Knoble <ben.knoble+vim@gmail.com>
+" Maintainer:	Konfekt
+" Original Source:	https://github.com/JalaiAmitahl/maven-compiler.vim/blob/master/compiler/mvn.vim
+"                   (Copyright Dan Taylor, distributed under the same terms as LICENSE)
+" Original Source:	https://github.com/mikelue/vim-maven-plugin/blob/master/compiler/maven.vim
+"                   (distributed under same terms as LICENSE per
+"                   https://github.com/mikelue/vim-maven-plugin/issues/13)
+" Last Change:	2024 Nov 12
+
+if exists("current_compiler")
+  finish
+endif
+let current_compiler = "maven"
+
+CompilerSet makeprg=mvn\ --batch-mode
+
+" Error message for POM
+CompilerSet errorformat=[FATAL]\ Non-parseable\ POM\ %f:\ %m%\\s%\\+@%.%#line\ %l\\,\ column\ %c%.%#,
+CompilerSet errorformat+=[%tRROR]\ Malformed\ POM\ %f:\ %m%\\s%\\+@%.%#line\ %l\\,\ column\ %c%.%#
+
+" Java related build messages
+CompilerSet errorformat+=[%tARNING]\ %f:[%l\\,%c]\ %m
+CompilerSet errorformat+=[%tRROR]\ %f:[%l\\,%c]\ %m
+CompilerSet errorformat+=%A[%t%[A-Z]%#]\ %f:[%l\\,%c]\ %m,%Z
+CompilerSet errorformat+=%A%f:[%l\\,%c]\ %m,%Z
+
+" jUnit related build messages
+CompilerSet errorformat+=%+E\ \ %#test%m,%Z
+CompilerSet errorformat+=%+E[ERROR]\ Please\ refer\ to\ %f\ for\ the\ individual\ test\ results.
+" Message from JUnit 5(5.3.X), TestNG(6.14.X), JMockit(1.43), and AssertJ(3.11.X)
+CompilerSet errorformat+=%+E%>[ERROR]\ %.%\\+Time\ elapsed:%.%\\+<<<\ FAILURE!,
+CompilerSet errorformat+=%+E%>[ERROR]\ %.%\\+Time\ elapsed:%.%\\+<<<\ ERROR!,
+CompilerSet errorformat+=%+Z%\\s%#at\ %f(%\\f%\\+:%l),
+CompilerSet errorformat+=%+C%.%#
+
+" Misc message removal
+CompilerSet errorformat+=%-G[INFO]\ %.%#,
+CompilerSet errorformat+=%-G[debug]\ %.%#