Merge branch 'master' into v2.1

diff --cc src/jit/bcsave.lua
index 4935ea8f561eb6efa5327e4abd5715c1af716563,58351c160f46aa8092378835f6290e2ef87218c0..42d7240b0f3da981ec70ca15f2c7d778d4896eee
--- 1/src/jit/bcsave.lua
--- 2/src/jit/bcsave.lua
+++ b/src/jit/bcsave.lua
@@@ -132,8 -118,8 +132,8 @@@ en
  local function bcsave_c(ctx, output, s)
    local fp = savefile(output, "w")
    if ctx.type == "c" then
 -    fp:write(string.format([[
 +    fp:write(format([[
- #ifdef _cplusplus
+ #ifdef __cplusplus
  extern "C"
  #endif
  #ifdef _WIN32