Move regression tests of the C front-end to a suitable folder, again

These tests aren't specific to building hybrid binaries, they just use parts of
C front-end that are GCC-specific. Thus place them in the ansi-c folder and use
the gcc-only tag.

Author: tautschnig

regression/goto-gcc/builtin_is/main.c renamed to regression/ansi-c/builtin_is/main.c

@@ -1,4 +1,4 @@
-KNOWNBUG
+KNOWNBUG gcc-only
 main.c
 
 ^EXIT=1$

regression/goto-gcc/builtin_is/test.desc renamed to regression/ansi-c/builtin_is/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+KNOWNBUG gcc-only
 main.c
 
 ^EXIT=1$

regression/goto-gcc/builtin_va_copy_lvalue/main.c renamed to regression/ansi-c/builtin_va_copy_lvalue/main.c

@@ -1,4 +1,4 @@
-CORE
+CORE gcc-only
 main.c
 
 ^EXIT=1$

regression/goto-gcc/builtin_va_copy_lvalue/test.desc renamed to regression/ansi-c/builtin_va_copy_lvalue/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+KNOWNBUG gcc-only
 main.c
 
 ^EXIT=1$

regression/goto-gcc/builtin_va_copy_two/main.c renamed to regression/ansi-c/builtin_va_copy_two/main.c

@@ -1,4 +1,4 @@
-CORE
+CORE gcc-only
 main.c
 
 ^EXIT=1$

regression/goto-gcc/builtin_va_end_one/test.desc renamed to regression/ansi-c/builtin_va_copy_two/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+KNOWNBUG gcc-only
 main.c
 
 ^EXIT=1$

regression/goto-gcc/builtin_va_end_lvalue/main.c renamed to regression/ansi-c/builtin_va_end_lvalue/main.c

@@ -1,4 +1,4 @@
-KNOWNBUG
+KNOWNBUG gcc-only
 main.c
 
 ^EXIT=1$