Zig 0.9.0 Regression: can't import <core_cm3.h>

[foldl]

Zig Version

0.9.0

Steps to Reproduce

0.9.0 fails to import <core_cm3.h> while 0.8.0 is OK.

1. aaa.h

   #pragma once
   
   typedef enum IRQn
   {
   /* -------------------  Cortex-M3 Processor Exceptions Numbers  ------------------- */
     NonMaskableInt_IRQn           = -14,      /*!<  2 Non Maskable Interrupt          */
     HardFault_IRQn                = -13,      /*!<  3 HardFault Interrupt             */
     MemoryManagement_IRQn         = -12,      /*!<  4 Memory Management Interrupt     */
     BusFault_IRQn                 = -11,      /*!<  5 Bus Fault Interrupt             */
     UsageFault_IRQn               = -10,      /*!<  6 Usage Fault Interrupt           */
     SVCall_IRQn                   =  -5,      /*!< 11 SV Call Interrupt               */
     DebugMonitor_IRQn             =  -4,      /*!< 12 Debug Monitor Interrupt         */
     PendSV_IRQn                   =  -2,      /*!< 14 Pend SV Interrupt               */
     SysTick_IRQn                  =  -1,      /*!< 15 System Tick Interrupt           */
   } IRQn_Type;
   
   /* --------  Configuration of the Cortex-M3 Processor and Core Peripherals  ------- */
   #define __CM3_REV                 0x0201    /*!< Core revision r2p1                              */
   #define __MPU_PRESENT             0         /*!< MPU present or not                              */
   #define __NVIC_PRIO_BITS          3         /*!< Number of Bits used for Priority Levels         */
   #define __Vendor_SysTickConfig    0         /*!< Set to 1 if different SysTick Config is used    */
   
   #include <core_cm3.h>                       /* Processor and core peripherals                    */

2. zbug.zig

   const cm3 = @cImport({
       @cInclude("aaa.h");
   });
   
   export fn tool() c_int {
       return cm3.HardFault_IRQn;
   }

3. build zbug.zig

   zig build-obj -target thumb-freestanding-none -mcpu cortex_m3 -I CMSIS_INC_PATH -I . zbug.zig

Expected Behavior

It should compile.

Actual Behavior

Using 0.9.0:

.\zbug.zig:1:13: error: C import failed
const cm3 = @cImport({
            ^
.\zbug.zig:1:13: note: libc headers not available; compilation does not link against libc
const cm3 = @cImport({
            ^
.../CMSIS/Include\core_cm3.h:138:6: note: "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
    #error "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
     ^
.\zbug.zig:6:12: note: referenced here
    return cm3.HardFault_IRQn;
           ^

[foldl]

It's reported because defined (__VFP_FP__) && !defined(__SOFTFP__) for Cortex M3. Code of core_cm3.h:

https://github.com/ARM-software/CMSIS/blob/f2cad4345783c948ed4a7f5cdb02cdc0856366f1/CMSIS/Include/core_cm3.h#L138