compiler/testdata: add missing error cases

This commit adds error cases that weren't covered before. They were
identified by looking at the coverage numbers for pkg/compiler.

Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>

pkg/compiler/testdata/errors.txt

@@ -139,6 +139,7 @@ foo$70() ("foo")		### unexpected string "foo", expect attribute
 foo$71() (42)			### unexpected int 42, expect attribute
 foo$72() (disabled, disabled)	### duplicate syscall foo$72 attribute disabled
 foo$73(a int32[int_flags, 2])	### align argument of int32 is not supported unless first argument is a range
+foo$74() (int8:1)		### unexpected ':'
 
 opt {				### struct uses reserved name opt
 	f1	int32
@@ -167,6 +168,7 @@ s3 {
 	f7	int32:33	### bitfield of size 33 is too large for base type of size 32
 	f8	const[0, int32:C1]	### literal const bitfield sizes are not supported
 	f9	const[0]	### wrong number of arguments for type const, expect value, base type
+	f10	int8:1:1	### unexpected ':'
 } [packed, align[4]]
 
 s5 {
@@ -201,6 +203,10 @@ s13 {
 	f1	int8
 } [size[0[0]]]			### size attribute has colon or args
 
+s14 {
+	f1	int8
+} [size[1, 2]]			### size attribute is expected to have 1 argument
+
 u3 [
 	f1	int8
 	f2	int32

pkg/compiler/testdata/errors2.txt

@@ -157,15 +157,24 @@ slen1 {
 	f7 len[syscall:b, int32]	### len target b does not exist
 	f8 offsetof[parent, int32]	### offsetof must refer to fields
 	f9 offsetof[slen1, int32]	### offsetof must refer to fields
+	f10 len[f0:syscall:b, int32]	### syscall can't be in the middle of path expressions
+	f11 len[slen3:a, int32]		### len path slen3 does not refer to a struct
 	slen2 ptr[in, array[slen2]]
 	slen21 slen2
+	slen3 slen3
 	slen22 array[slen2]
 }
 
 slen2 {
-	f int32
+	f	int32
+	f1	slen3
 }
 
+slen3 [
+	a int32
+	b int32
+]
+
 # Resource ctor tests.
 
 resource r100[int32]		### resource r100 can't be created (never mentioned as a syscall return value or output argument/field)