Fix compiler errors when built with C++ modules using clang (#67)

lsqpack.h

@@ -29,10 +29,6 @@ SOFTWARE.
 #ifndef LSQPACK_H
 #define LSQPACK_H 1
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #include <limits.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -42,6 +38,10 @@ extern "C" {
 typedef SSIZE_T ssize_t;
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define LSQPACK_MAJOR_VERSION 2
 #define LSQPACK_MINOR_VERSION 5
 #define LSQPACK_PATCH_VERSION 5
@@ -616,13 +616,21 @@ enum lsqpack_tnv
     LSQPACK_TNV_X_FRAME_OPTIONS_SAMEORIGIN = 98, /* "x-frame-options" "sameorigin" */
 };
 
+#ifdef __cplusplus
+}
+#endif
+
 
 /*
  * Internals follow.  The internals are subject to change without notice.
  */
 
 #include <sys/queue.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* It takes 11 bytes to encode UINT64_MAX as HPACK integer */
 #define LSQPACK_UINT64_ENC_SZ 11u
 

lsxpack_header.h

@@ -1,14 +1,14 @@
 #ifndef LSXPACK_HEADER_H_v208
 #define LSXPACK_HEADER_H_v208
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #include <assert.h>
 #include <stdint.h>
 #include <string.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #ifndef LSXPACK_MAX_STRLEN
 #define LSXPACK_MAX_STRLEN UINT16_MAX
 #endif