math: fix signed int left shift ub in sqrt

Both sqrt and sqrtf shifted the signed exponent as signed int to adjust
the bit representation of the result. There are signed right shifts too
in the code but those are implementation defined and are expected to
compile to arithmetic shift on supported compilers and targets.

src/math/sqrt.c

@@ -179,7 +179,6 @@ double sqrt(double x)
 	ix1 = q1>>1;
 	if (q&1)
 		ix1 |= sign;
-	ix0 += m << 20;
-	INSERT_WORDS(z, ix0, ix1);
+	INSERT_WORDS(z, ix0 + ((uint32_t)m << 20), ix1);
 	return z;
 }

src/math/sqrtf.c

@@ -78,7 +78,6 @@ float sqrtf(float x)
 		}
 	}
 	ix = (q>>1) + 0x3f000000;
-	ix += m << 23;
-	SET_FLOAT_WORD(z, ix);
+	SET_FLOAT_WORD(z, ix + ((uint32_t)m << 23));
 	return z;
 }