STM32L496xG: increase IAR heap size

Author: jeromecoutant

targets/TARGET_STM/TARGET_STM32L4/TARGET_STM32L496xG/device/TOOLCHAIN_IAR/stm32l496xx.icf

@@ -20,7 +20,8 @@ define region SRAM1_region = mem:[from __region_SRAM1_start__ to __region_SRAM1_
 
 /* Stack 1/8 and Heap 1/4 of RAM */
 define symbol __size_cstack__ = 0x8000;
-define symbol __size_heap__   = 0xa000;
+define symbol __size_heap__   = 0x10000;
+
 define block CSTACK    with alignment = 8, size = __size_cstack__   { };
 define block HEAP      with alignment = 8, size = __size_heap__     { };
 define block STACKHEAP with fixed order { block HEAP, block CSTACK };