tccpp : "tcc -E -P" : suppress empty lines

Also:
- regenerate all tests/pp/*.expect with gcc
- test "insert one space" feature
- test "0x1E-1" in asm mode case
- PARSE_FLAG_SPACES: ignore \f\v\r better
- tcc.h: move some things

tests/pp/15.expect

@@ -0,0 +1,7 @@
+return (long double)d;
+return A+++B;
+return A+ ++B;
+return A+++ +B;
+return 0x1E -1;
+XXX: return x+x-1 +1 -2;
+XXX: return x x 1 2 x;