Windows: use default shell env for ijar execution, so that .dlls can …

…be found.

On Windows, ijar.exe needs msys-2.0.dll and zlib1.dll in PATH.

Needed for #276.

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MOS_MIGRATED_REVID=114947735

src/main/java/com/google/devtools/build/lib/rules/java/BaseJavaCompilationHelper.java

@@ -172,6 +172,10 @@ protected Artifact createIjarAction(Artifact inputJar, boolean addPrefix) {
           .addInput(inputJar)
           .addOutput(interfaceJar)
           .setExecutable(ijarTarget)
+          // On Windows, ijar.exe needs msys-2.0.dll and zlib1.dll in PATH.
+          // Use default shell environment so that those can be found.
+          // TODO(dslomov): revisit this. If ijar is not msys-dependent, this is not needed.
+          .useDefaultShellEnvironment()
           .addArgument(inputJar.getExecPathString())
           .addArgument(interfaceJar.getExecPathString())
           .setProgressMessage("Extracting interface " + ruleContext.getLabel())