*: Move some dictionary functions to typval.h and use char*

Also fixes buffer reusage in setmatches() and complete().

test/functional/eval/match_functions_spec.lua

@@ -0,0 +1,39 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local eq = helpers.eq
+local clear = helpers.clear
+local funcs = helpers.funcs
+local command = helpers.command
+
+before_each(clear)
+
+describe('setmatches()', function()
+  it('correctly handles case when both group and pattern entries are numbers',
+  function()
+    command('hi def link 1 PreProc')
+    eq(0, funcs.setmatches({{group=1, pattern=2, id=3, priority=4}}))
+    eq({{
+      group='1',
+      pattern='2',
+      id=3,
+      priority=4,
+    }}, funcs.getmatches())
+    eq(0, funcs.setmatches({{group=1, pattern=2, id=3, priority=4, conceal=5}}))
+    eq({{
+      group='1',
+      pattern='2',
+      id=3,
+      priority=4,
+      conceal='5',
+    }}, funcs.getmatches())
+    eq(0, funcs.setmatches({{group=1, pos1={2}, pos2={6}, id=3, priority=4, conceal=5}}))
+    eq({{
+      group='1',
+      pos1={2},
+      pos2={6},
+      id=3,
+      priority=4,
+      conceal='5',
+    }}, funcs.getmatches())
+  end)
+end)