This reduces the size of the iommu_gas.o binary by 400 bytes.
With a test that inserts and removes nodes from a 32k element tree, and with both executables having names of the same length (which, strangely, seems to matter a lot), the runtime performance is improved slightly. The careful naming of executables means that the 'now' times reported here are pretty close to the 'new' times reported with the most recent change to tree.h.
```
x plain.lip1.now.res
+ plain.lip1.new.res
+-------------------------------------------------------------------------------------+
| + |
| + |
| + x |
|+ + xx x x |
|+ + +x+++++ + xxxx+xx * x++ x+ x*x+ xx xx ++ + x x|
| |________M___|_____A________M___A______|__________| |
+-------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 24 65.87033 68.598749 66.742854 66.855717 0.67769376
+ 24 65.577766 67.744526 66.042251 66.422521 0.68442411
Difference at 95.0% confidence
-0.433197 +/- 0.39577
-0.647958% +/- 0.591977%
(Student's t, pooled s = 0.681067)
x plain.lip2.now.res
+ plain.lip2.new.res
+-------------------------------------------------------------------------------------+
| + + + xx |
| + +++ ++ x xx xx |
|++++++++ ++ + + + + + xxx xxxxxxx x x x x x|
| |____M__A_______| |_______M_A_________| |
+-------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 24 66.34505 66.986635 66.454038 66.493225 0.15431923
+ 24 65.72316 66.179581 65.816634 65.857818 0.11997022
Difference at 95.0% confidence
-0.635407 +/- 0.0803177
-0.955596% +/- 0.120791%
(Student's t, pooled s = 0.138216)
x plain.lip3.now.res
+ plain.lip3.new.res
+-------------------------------------------------------------------------------------+
| + x + |
| ++ + x xx+ x+xx |
|+ ++ + ++ + + + + x +x x xx+ x*+x +x+x*x x x x x|
| |_______________M__A________|_________|____A______________| |
+-------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 24 38.360441 39.1466 38.555815 38.626227 0.21297425
+ 24 37.935013 38.705 38.243775 38.276296 0.27493776
Difference at 95.0% confidence
-0.349931 +/- 0.142902
-0.905943% +/- 0.369962%
(Student's t, pooled s = 0.245915)
x plain.lip4.now.res
+ plain.lip4.new.res
+-------------------------------------------------------------------------------------+
| + |
| + x |
| ++++ x x x |
|+ ++++ + x x x x x x |
|++++++++ ++ + + x xx xxxxxxxxx x x|
| |__M_A___| |____A____| |
+-------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 24 55.082459 55.252462 55.158365 55.160541 0.038314475
+ 24 54.606313 54.784864 54.640612 54.649147 0.036675415
Difference at 95.0% confidence
-0.511394 +/- 0.0217936
-0.927102% +/- 0.0395095%
(Student's t, pooled s = 0.0375039)
x plain.lip5.now.res
+ plain.lip5.new.res
+-------------------------------------------------------------------------------------+
| + x |
| + x |
| + x |
| + x |
| + x |
| + x |
| + x |
|++ x |
|+++ xx |
|+++ xxx|
|+++ xxx|
|+++ xxxx|
|+++ xxxx|
||A| |A||
+-------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 24 87.776935 87.888856 87.846299 87.843616 0.029030408
+ 24 84.851598 84.92715 84.884437 84.886523 0.021015438
Difference at 95.0% confidence
-2.95709 +/- 0.0147262
-3.36632% +/- 0.0167641%
(Student's t, pooled s = 0.0253418)
```