[builtins] Add void prototype to unprototyped functions

[aykevl]

Summary

This patch replaces () prototypes with (void) prototypes, to avoid declaring these functions as variadic functions.

---

Found while porting compiler-rt to the AVR platform. There are still some Clang bugs where it uses the wrong address space for variadic functions, and this patch works around that. Of course this should also be fixed in Clang, but I think the effort started in D78491 is a much more systematic approach (and will probably take a while until it is finished). Until then, this patch avoids some accidental variadic functions.

[MaskRay]

LGTM. Though hope you can address more issues in one patch.

[aykevl]

Thanks for the review!

In D78641#1996984, @MaskRay wrote:

LGTM. Though hope you can address more issues in one patch.

Yeah I just fixed things as I went through supporting AVR (D78205 was to get the builtins to compile, this patch was to get the tests to compile). If I find more issues, I'll try to bundle all related changes in one patch.

compiler-rt/test/builtins/Unit/fp_test.h

switch(expected){
         case GREATER_0:
             return ">0";
         default:
             return "";
     }
     return "";
 }
 
-static inline uint16_t makeQNaN16()
+static inline uint16_t makeQNaN16(void)
 {
     return fromRep16(0x7e00U);
 }
 
-static inline float makeQNaN32()
+static inline float makeQNaN32(void)
 {
     return fromRep32(0x7fc00000U);
 }
 
-static inline double makeQNaN64()
+static inline double makeQNaN64(void)
 {
     return fromRep64(0x7ff8000000000000UL);
 }
 
 #if __LDBL_MANT_DIG__ == 113
-static inline long double makeQNaN128()
+static inline long double makeQNaN128(void)
 {
     return fromRep128(0x7fff800000000000UL, 0x0UL);
 }
 #endif
 
 static inline uint16_t makeNaN16(uint16_t rand)
 {
     return fromRep16(0x7c00U | (rand & 0x7fffU));

 
 #if __LDBL_MANT_DIG__ == 113
 static inline long double makeNaN128(uint64_t rand)
 {
     return fromRep128(0x7fff000000000000UL | (rand & 0xffffffffffffUL), 0x0UL);
 }
 #endif
 
-static inline uint16_t makeInf16()
+static inline uint16_t makeInf16(void)
 {
     return fromRep16(0x7c00U);
 }
 
-static inline float makeInf32()
+static inline float makeInf32(void)
 {
     return fromRep32(0x7f800000U);
 }
 
-static inline double makeInf64()
+static inline double makeInf64(void)
 {
     return fromRep64(0x7ff0000000000000UL);
 }
 
 #if __LDBL_MANT_DIG__ == 113
-static inline long double makeInf128()
+static inline long double makeInf128(void)
 {
     return fromRep128(0x7fff000000000000UL, 0x0UL);
 }
 #endif