Add a flag to evaluate the top level transitions in Skyframe

This adds a new PrepareAnalysisPhaseFunction, which started out as a copy of
some existing code from SkyframeExecutor, BuildView, AnalysisPhaseRunner,
AnalysisUtils, and ConfigurationResolver, which was then modified to work
inside Skyframe.

Most of our tests already work with the new code, except for some of the tests
related to configuration trimming in combination with dependency cycles. The
reason for this is that we can only recover from dependency cycles at the end
of a Skyframe invocation, but never inside a Skyframe invocation. The new code
therefore cannot return partial results like the old code.

This seems to make null builds a bit faster. In my testing, I saw null build
times for a single test target go from ~50ms to ~40ms. This is probably due to
slightly better caching - it seems that computing the configuration transitions
and top-level targets is non-negligible, even if there's only a single
top-level configuration for a single top-level target.

This might be an even bigger win if there are a lot of top-level targets and
configurations.

PiperOrigin-RevId: 207083192
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
index 09bdcd3..ac9228c 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyFunctions.java
@@ -79,6 +79,8 @@
   // Non-hermetic because accesses package locator
   static final SkyFunctionName TARGET_PATTERN_PHASE =
       SkyFunctionName.createNonHermetic("TARGET_PATTERN_PHASE");
+  static final SkyFunctionName PREPARE_ANALYSIS_PHASE =
+      SkyFunctionName.createNonHermetic("PREPARE_ANALYSIS_PHASE");
   static final SkyFunctionName RECURSIVE_PKG = SkyFunctionName.createHermetic("RECURSIVE_PKG");
   static final SkyFunctionName TRANSITIVE_TARGET =
       SkyFunctionName.createHermetic("TRANSITIVE_TARGET");