Move RcuVector and relevant support classes to vespalib

Having RCU support available across all our C++ modules open up
new opportunities for optimizations.

This changes the following:
- `RcuVector` moved from `searchlib` to `vespalib`
- `MemoryUsage` moved from `searchlib` to `vespalib`
- Introduce a simplified, more generic `GrowStrategy` in `vespalib`
  used by the moved `RcuVector` which does not have any notion of
  documents. Existing searchlib `GrowStrategy` gets a simple function
  to convert to this generic strategy.

1 files changed, 1 insertions, 1 deletions

diff --git a/searchlib/src/tests/attribute/attribute_test.cpp b/searchlib/src/tests/attribute/attribute_test.cpp
index 537fa07bada..c71e51b2040 100644
--- a/searchlib/src/tests/attribute/attribute_test.cpp
+++ b/searchlib/src/tests/attribute/attribute_test.cpp
@@ -1816,7 +1816,7 @@ AttributeTest::testGeneration(const AttributePtr & attr, bool exactStatus)
     EXPECT_EQUAL(1u, ia.getCurrentGeneration());
     uint64_t lastAllocated;
     uint64_t lastOnHold;
-    MemoryUsage changeVectorMemoryUsage(attr->getChangeVectorMemoryUsage());
+    vespalib::MemoryUsage changeVectorMemoryUsage(attr->getChangeVectorMemoryUsage());
     size_t changeVectorAllocated = changeVectorMemoryUsage.allocatedBytes();
     if (exactStatus) {
         EXPECT_EQUAL(2u + changeVectorAllocated, ia.getStatus().getAllocated());