[analyzer] Add range constructor to CallDescriptionMap

[gamesh411]

Summary

CallDescriptionMap benefits from a range constructor when the
CallDescription and mapped type pairs cannot be constructed at once, but
are built incrementally.

[steakhal]

LGTM

clang/unittests/StaticAnalyzer/CallDescriptionTest.cpp

24–28

I'm not even sure we need this assertion though.

38

Maybe the ResultMap should also follow this and declare the ctor overload.

[gamesh411]

Remove static asserts as it only makes the tests more brittle

clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h

template <typename T> class CallDescriptionMap {
   // descriptions (eg., the ones for C functions that just match the name).
   std::vector<std::pair<CallDescription, T>> LinearMap;
 
 public:
   CallDescriptionMap(
       std::initializer_list<std::pair<CallDescription, T>> &&List)
       : LinearMap(List) {}
 
+  template <typename InputIt>
+  CallDescriptionMap(InputIt First, InputIt Last) : LinearMap(First, Last) {}
+
   ~CallDescriptionMap() = default;
 
   // These maps are usually stored once per checker, so let's make sure
   // we don't do redundant copies.
   CallDescriptionMap(const CallDescriptionMap &) = delete;
   CallDescriptionMap &operator=(const CallDescription &) = delete;
 
   LLVM_NODISCARD const T *lookup(const CallEvent &Call) const {

clang/unittests/StaticAnalyzer/CallDescriptionTest.cpp

 #include "clang/Tooling/Tooling.h"
 #include "gtest/gtest.h"
 #include <type_traits>
 
 namespace clang {
 namespace ento {
 namespace {
 
+using ArgsContainer = std::vector<std::pair<CallDescription, bool>>;
+
+static_assert(
+    std::is_constructible<CallDescriptionMap<bool>,
+                          decltype(std::declval<ArgsContainer>().begin()),
+                          decltype(std::declval<ArgsContainer>().end())>(),
+    "should be range constructible");
+
 // A wrapper around CallDescriptionMap<bool> that allows verifying that
 // all functions have been found. This is needed because CallDescriptionMap
 // isn't supposed to support iteration.
 class ResultMap {
   size_t Found, Total;
   CallDescriptionMap<bool> Impl;
 
 public:
   ResultMap(std::initializer_list<std::pair<CallDescription, bool>> Data)
       : Found(0),
         Total(std::count_if(Data.begin(), Data.end(),
                             [](const std::pair<CallDescription, bool> &Pair) {
                               return Pair.second == true;
                             })),
         Impl(std::move(Data)) {}
 
   const bool *lookup(const CallEvent &Call) {