Disable partial inlining by default and add a flag for it. (#4191)

Locally I saw a 10% speedup on j2cl but reports of regressions have
arrived, so let's disable it for now pending investigation. The option added
here should make it easy to experiment.

1 files changed, 1 insertions, 2 deletions

diff --git a/src/passes/Inlining.cpp b/src/passes/Inlining.cpp
index e1ae4c2a8..7467d2559 100644
--- a/src/passes/Inlining.cpp
+++ b/src/passes/Inlining.cpp
@@ -641,8 +641,7 @@ private:
     // without an else.
 
     // Find the number of ifs.
-    // TODO: Investigate more values here. 4 appears useful on real-world code.
-    const Index MaxIfs = 4;
+    const Index MaxIfs = options.inlining.partialInliningIfs;
     Index numIfs = 0;
     while (getIf(body, numIfs) && numIfs <= MaxIfs) {
       numIfs++;