Add global GCC version check

We can set some of them lower than 13 if necessary on a per-port basis.
At least esp32 and arm ports all use 13 from what I could see.

Author: jepler

py/circuitpy_mpconfig.h

@@ -599,3 +599,19 @@ void background_callback_run_all(void);
 // Enable compiler functionality.
 #define MICROPY_ENABLE_COMPILER (1)
 #define MICROPY_PY_BUILTINS_COMPILE (1)
+
+#ifndef CIRCUITPY_MIN_GCC_VERSION
+#define CIRCUITPY_MIN_GCC_VERSION 13
+#endif
+
+#if defined(__GNUC__)
+#if __GNUC__ < CIRCUITPY_MIN_GCC_VERSION
+// (the 3 level scheme here is required to get expansion & stringization
+// correct)
+#define DO_PRAGMA(x) _Pragma(#x)
+#define DO_ERROR_HELPER(x) DO_PRAGMA(GCC error #x)
+#define DO_ERROR(x) DO_ERROR_HELPER(Minimum GCC version x \
+    -- older versions are known to miscompile CircuitPython)
+DO_ERROR(CIRCUITPY_MIN_GCC_VERSION);
+#endif
+#endif

py/circuitpy_mpconfig.mk

@@ -697,6 +697,10 @@ CFLAGS += -DCIRCUITPY_TUSB_ATTR_USBRAM=$(CIRCUITPY_TUSB_ATTR_USBRAM)
 CIRCUITPY_SWO_TRACE ?= 0
 CFLAGS += -DCIRCUITPY_SWO_TRACE=$(CIRCUITPY_SWO_TRACE)
 
+# Check for a minimum GCC version during build (set to 0 to disable)
+CIRCUITPY_MIN_GCC_VERSION ?= 13
+CFLAGS += -DCIRCUITPY_MIN_GCC_VERSION=$(CIRCUITPY_MIN_GCC_VERSION)
+
 # Define an equivalent for MICROPY_LONGINT_IMPL, to pass to $(MPY-TOOL) in py/mkrules.mk
 # $(MPY-TOOL) needs to know what kind of longint to use (if any) to freeze long integers.
 # This should correspond to the MICROPY_LONGINT_IMPL definition in mpconfigport.h.