Bug 1752870 - Filter code ranges before searching. r=rhunt

When searching a lazy stub segment for the code range that holds a
particular PC value, we can quickly exclude segments that are
guaranteed not to match by comparing the PC to the values at the
segment's endpoints - the code ranges in a segment are sorted, and
this filtering will cause the search to skip most segments.  This very
significantly reduces the time spent in the search.

Differential Revision: https://phabricator.services.mozilla.com/D137518

js/src/wasm/WasmCode.cpp

@@ -680,6 +680,11 @@ bool LazyStubSegment::addIndirectStubs(
 }
 
 const CodeRange* LazyStubSegment::lookupRange(const void* pc) const {
+  // Do not search if the search will not find anything.  There can be many
+  // segments, each with many entries.
+  if (pc < base() || pc >= base() + length()) {
+    return nullptr;
+  }
   return LookupInSorted(codeRanges_,
                         CodeRange::OffsetInCode((uint8_t*)pc - base()));
 }