Changed __attribute__(( constructor in main.cpp, with update provided by Victor_PV, so fix issue with premain not being called first in the init seequence

STM32F1/cores/maple/main.cpp

@@ -30,7 +30,7 @@ extern void init(void);
 
 // Force init to be called *first*, i.e. before static object allocation.
 // Otherwise, statically allocated objects that need libmaple may fail.
- __attribute__(( constructor )) void premain() {
+ __attribute__(( constructor (0) )) void premain() {
     init();
 }