For consistency, replace some existing extern "C" with __PTW32_* macros

used elsewhere.

ChangeLog

@@ -1,6 +1,10 @@
 2018-08-10  Ross Johnson <ross dot johnson at homemail dot com dot au>
 
 	* Makefile (clean): remove *.idb files.
+	* dll.c: replace 'extern "C"' with macros __PTW32_BEGIN_C_DECLS/__PTW32_BEGIN_C_DECLS
+	for consistency tidy-up; add comment re __ptw32_autostatic_anchor() function.
+	* implement.h (__ptw32_autostatic_anchor): add __PTW32_BEGIN_C_DECLS/__PTW32_BEGIN_C_DECLS
+	envelope.
 
 2018-08-08  Ross Johnson <ross dot johnson at homemail dot com dot au>
 

dll.c

@@ -49,13 +49,9 @@
 #pragma warning( disable : 4100 )
 #endif
 
-#if defined(__cplusplus)
-/*
- * Dear c++: Please don't mangle this name. -thanks
- */
-extern "C"
-#endif				/* __cplusplus */
-  BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
+__PTW32_BEGIN_C_DECLS
+
+BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
 {
   BOOL result =  __PTW32_TRUE;
 
@@ -90,6 +86,8 @@ extern "C"
 
 }				/* DllMain */
 
+__PTW32_END_C_DECLS
+
 #endif /* !PTW32_STATIC_LIB */
 
 #if ! defined (__PTW32_BUILD_INLINED)
@@ -157,11 +155,19 @@ static int (*msc_dtor)(void) = on_process_exit;
 
 #endif /* defined(__MINGW32__) || defined(_MSC_VER) */
 
+__PTW32_BEGIN_C_DECLS
+
 /* This dummy function exists solely to be referenced by other modules
  * (specifically, in implement.h), so that the linker can't optimize away
  * this module. Don't call it.
+ *
+ * Shouldn't work if we are compiling via pthreads.c
+ * (whole library single translation unit)
+ * Leaving it here in case it affects small-static builds.
  */
 void __ptw32_autostatic_anchor(void) { abort(); }
 
+__PTW32_END_C_DECLS
+
 #endif /*  __PTW32_STATIC_LIB */
 

implement.h

@@ -135,11 +135,13 @@ static void __ptw32_set_errno(int err) { errno = err; SetLastError(err); }
  * Don't allow the linker to optimize away dll.obj (dll.o) in static builds.
  */
 #if defined (__PTW32_STATIC_LIB) && defined (__PTW32_BUILD) && !defined (__PTW32_TEST_SNEAK_PEEK)
+__PTW32_BEGIN_C_DECLS
   void __ptw32_autostatic_anchor(void);
 # if defined(__GNUC__)
     __attribute__((unused, used))
 # endif
   static void (*local_autostatic_anchor)(void) = __ptw32_autostatic_anchor;
+__PTW32_END_C_DECLS
 #endif
 
 typedef enum